BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Ergün Yalçın (Bilkent University)
DTSTART:20201009T100000Z
DTEND:20201009T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/1
DESCRIPTION:Title: The Dade Group of a Finite Group and Dimension Functions\nby
Ergün Yalçın (Bilkent University) as part of Yeditepe Mathematics Semi
nars\n\n\nAbstract\nLet $G$ be a finite group and $k$ an algebraically clo
sed field of characteristic\n$p > 0$. We define the notion of a Dade $kG$-
module as a generalization of endopermutation modules for $p$-groups. We s
how that under a suitable equivalence relation\, the set of equivalence cl
asses of Dade $kG$-modules forms a group under tensor product\, and the gr
oup obtained this way is isomorphic to the Dade group $D(G)$ defined by La
ssueur $[2]$.\n\nWe also consider the subgroup $D^\\Omega (G)$ of $D(G)$
generated by relative syzygies\n$\\Omega X$\, where $X$ is a finite $G$-se
t. Let $C(G\; p)$ denote the group of superclass\nfunctions defined on the
p-subgroups of G. There are natural generators $\\omega_X$\nof $C(G\; p)$
. We prove that there is a well-defined group homomorphism $\\psi_G :\nC(G
\; p) \\to D^\\Omega (G)$ that sends $\\omega_X$ to $ \\Omega_X$.\n\nThe
main theorem is the verification that the subgroup of $C(G\; p)$ consistin
g\nof the dimension functions of $k$-orientable real representations of $G
$ lies in the\nkernel of $\\psi_G$. In the proof we consider Moore $G$-spa
ces which are the equivariant\nversions of spaces which have nonzero reduc
ed homology in only one dimension.\n\nThis talk is about a theorem in modu
lar representation theory whose proof is\ntopological using equivariant ho
motopy theory and homological algebra over\norbit category. I will give al
l necessary definitions to make it possible to follow\nthe talk and provid
e examples to motivate the theorems.\n\nThis is a joint work with Matthew
Gelvin $[1]$.\n\n$\\mathbf{References}$\n\n$[1]$ M. Gelvin and E. Yalçın
\, Dade Groups for Finite Groups and Dimension Functions\, preprint\, 2020
(arXiv:2007.05322v2).\n\n$[2]$ C. Lassueur\, The Dade group of a finite g
roup\, J. Pure Appl. Algebra\, 217 (2013)\,\n97-113.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aslı Güçlükan İlhan (Dokuz Eylül University)
DTSTART:20201016T100000Z
DTEND:20201016T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/2
DESCRIPTION:Title: $\\omega$-Weighted Digraphs and Local Complementations\nby A
slı Güçlükan İlhan (Dokuz Eylül University) as part of Yeditepe Math
ematics Seminars\n\n\nAbstract\nIn this talk\, we introduce $\\omega$-weig
hted digraphs for a given dimension function $\\omega$. We generalize the
notion of a local complementation to $\\omega$-weighted digraphs. Then we
establish a bijection between isomorphism classes of $\\omega$-weighted di
graphs up to local complementations and the isomorphism classes of weakly
$\\mathbb{Z}_2^n$-equivariant small covers over a product of simplices.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kazım İlhan İkeda (Boğaziçi University)
DTSTART:20201030T100000Z
DTEND:20201030T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/3
DESCRIPTION:Title: On the Langlands reciprocity and functoriality principles\nb
y Kazım İlhan İkeda (Boğaziçi University) as part of Yeditepe Mathema
tics Seminars\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atabey Kaygun (İstanbul Technical University)
DTSTART:20201106T140000Z
DTEND:20201106T150000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/4
DESCRIPTION:Title: Generalized Weyl Algebras\, Birational Equivalences and Gelfand
Kirillov Conjecture\nby Atabey Kaygun (İstanbul Technical University)
as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nRank $1$ generali
zed Weyl algebras (GWAs) form an interesting class of algebras that includ
e (quantum) enveloping algebra of $sl(2)$ and some interesting quantum gro
ups of rank $1$ and $2$. In this talk I will define GWAs and then explain
how these examples fit into the framework of GWAs. Birational equivalence\
, on the other hand\, is a tool (commutative) algebraic geometers use quit
e extensively. Interestingly\, GWAs are birationally equivalent to a smash
product with a torus of rank $1$. Time permitting\, I will talk about how
all of these relate to Gelfand-Kirillov conjecture.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Özgün Ünlü (Bilkent University)
DTSTART:20210108T100000Z
DTEND:20210108T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/5
DESCRIPTION:Title: Free Group Actions on Products of Two Equidimensional Spheres\nby Özgün Ünlü (Bilkent University) as part of Yeditepe Mathematics
Seminars\n\n\nAbstract\nWe will first review some known restrictions on fi
nite groups\nthat can act freely on products of two equidimensional sphere
s. Then we\nwill discuss some constructions of free actions of finite p-g
roups on\nproducts of two equidimensional spheres. Finally\, we will discu
ss some\nopen problems about free p-group actions on two equidimensional s
pheres.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Turgut Önder (Middle East Techinal University)
DTSTART:20201204T140000Z
DTEND:20201204T150000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/6
DESCRIPTION:Title: Existence of Almost Complex Foliations on Spheres\nby Turgut
Önder (Middle East Techinal University) as part of Yeditepe Mathematics
Seminars\n\n\nAbstract\nIntuitively\, a foliation on a manifold correspond
s to a partition of the manifold into connected\, immersed submanifolds of
the same dimension\, called leaves which form locally layers of a Euclide
an space. An almost complex foliation is a foliation whose tangent bundle
admits a complex structure. The existence problem of foliations on closed
manifolds is reduced to the existence problem of plane fields in 1970’s
by W. Thurston which can be attacked by algebraic topological methods. How
ever\, not much has been written about the existence problem of almost com
plex foliations. On spheres\, İ. Dibağ’s results provide concrete nece
ssary conditions in terms of the dimension of the sphere and the dimension
of the foliation. In this talk\, after reviewing some basic notions about
the foliations\, we will present some results in the other direction\, i.
e. about the sufficient conditions for the existence of almost complex fol
iations on spheres.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Özgür Kişisel (Middle East Techinal University)
DTSTART:20201211T140000Z
DTEND:20201211T150000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/7
DESCRIPTION:Title: On complex 4-nets\nby Özgür Kişisel (Middle East Techinal
University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nNets
are certain special line arrangements in the plane and they occur in vario
us contexts related to algebraic geometry\, such as resonance varieties\,
homology of Milnor fibers and fundamental groups of curve complements. We
will investigate nets in the complex projective plane $\\mathbb{CP}^2$. Le
t $m\\geq 3$ and $d\\geq 2$ be integers. An $(m\,d)$-net is a pencil of de
gree $d$ algebraic curves in $\\mathbb{CP}^2$ with a base locus of exactly
$d^2$ points\, which degenerates into a union of $d$ lines $m$ times. It
was conjectured that the only $4$-net is a $(4\,3)$-net called the Hessian
arrangement. I will outline our proof together with A. Bassa of this conj
ecture.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fatih Erman (İzmir İnstitute of Technology)
DTSTART:20201218T100000Z
DTEND:20201218T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/8
DESCRIPTION:Title: On the Existence of a Self-Adjoint Hamiltonian for a Singular In
teraction on Manifolds\nby Fatih Erman (İzmir İnstitute of Technolog
y) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nAccording to th
e postulates of Quantum Mechanics\, the dynamics of quantum systems are ge
nerated by a self-adjoint operator\, namely Hamiltonian operator associate
d with the energy of the system. Dirac delta potentials are known as one c
lass of singular interactions\, which have many applications in various ar
eas of physics. There are different mathematically rigorous approaches for
the description of such systems by some self-adjoint Hamiltonian operator
in $L^2(\\mathbb{R}^n)$. In this talk\, I would like to introduce the sub
ject in a rather elementary way and briefly discuss such interactions in o
ne dimension heuristically and from the Von Neumann's self-adjoint extensi
on point of view. Then\, I shall extend the same model onto the two and th
ree dimensional Cartan-Hadamard manifolds with Ricci curvature bounded bel
ow by describing the system in terms of "limit" of resolvent of the regula
rized version of the initial singular Hamiltonian. This will be accomplish
ed by the heat kernel defined on manifolds and its Li-Yau type of estimate
s.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Noyan Er (Dokuz Eylül University)
DTSTART:20201225T100000Z
DTEND:20201225T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/9
DESCRIPTION:Title: Pure Things\nby Noyan Er (Dokuz Eylül University) as part o
f Yeditepe Mathematics Seminars\n\n\nAbstract\nThis will be a down-to-eart
h that talk aims to spark interest\, especially among young researchers\,
in a notion at the crossroads of several fields of algebra\, including rep
resentation theory of algebras\, abelian group theory and ring theory\, na
mely purity. However\, whatever the path it may have followed historically
\, we will derive our motivation from a subject accessible to pretty much
every one with a basic understanding of linear algebra: systems of linear
equations.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Serdar Ay (Bilkent University)
DTSTART:20200508T100000Z
DTEND:20200508T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/12
DESCRIPTION:Title: Dilations of positive semidefinite kernels valued in operators
of barrelled VH-spaces\nby Serdar Ay (Bilkent University) as part of Y
editepe Mathematics Seminars\n\n\nAbstract\nA VH-space (Vector Hilbert Spa
ce in the sense of Loynes) is a complex complete locally convex space with
a topologically ordered $*$-space valued inner product. Examples of VH-sp
aces include the chain of locally Hilbert $C^*$-modules\, Hilbert $C^*$-mo
dules and Hilbert Spaces.\n \nIn this talk\, after a brief discussion of
VH-Spaces with examples and basic properties\, we state a general dilation
theorem for positive semidefinite kernels valued in adjointable operators
on a barrelled VH-space. We prove that\, under barrelledness assumption\,
a necessary and sufficient condition for the existence of a natural VH-sp
ace dilation\, or equivalently\, a reproducing kernel VH-space representat
ion of the kernel\, is satisfied automatically.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mehmet Akif Erdal (Yeditepe University)
DTSTART:20200306T100000Z
DTEND:20200306T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/13
DESCRIPTION:Title: Brown Fibration Categories and Enrichments in Monoidal Model Ca
tegories\nby Mehmet Akif Erdal (Yeditepe University) as part of Yedite
pe Mathematics Seminars\n\n\nAbstract\nIn this talk we will discuss Browns
categories of fibrant objects that are induced by enrichments over symmet
ric monoidal model categories. We will also show that various categories o
f operator algebras\, and their equivariant versions\, are examples of cat
egories of fibrant objects induced by enrichments. By using this\, we reco
ver known results that equivariant $KK$ and $E$-theories are triangulated.
\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tuna Bayraktar (Yeditepe University)
DTSTART:20200417T100000Z
DTEND:20200417T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/14
DESCRIPTION:Title: Minimal surfaces and smooth autonomous dynamical systems in 2D<
/a>\nby Tuna Bayraktar (Yeditepe University) as part of Yeditepe Mathemati
cs Seminars\n\n\nAbstract\nIn this talk\, an autonomous dynamical system
on a two-dimensional manifold $M$ will be identified with an exterior diff
erential system $\\left(\\Sigma\,\\mathcal{I}\\right)$\, where $\\Sigma$ i
s a three-dimensional Riemannian manifold in $\\mathbb{R}\\times TM\\simeq
J^1(\\mathbb{R}\,M)$ and $\\mathcal{I}$ is the Pfaffian system generated
by the contact forms on $\\Sigma$. We will show that it is possible to con
struct a minimal but not necessarily totally geodesic surface in $\\Sigma$
characterized by the corresponding dynamical system. As a particular case
\, a nontrivial minimal surface in the Heisenberg group will be discussed.
\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Degtyarev (Bilkent University)
DTSTART:20210507T100000Z
DTEND:20210507T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/16
DESCRIPTION:Title: Counting lines\, curves\, planes… in algebraic varieties\
nby Alexander Degtyarev (Bilkent University) as part of Yeditepe Mathemati
cs Seminars\n\n\nAbstract\nI will start from several classical but very si
mple\, almost high school level\, examples of algebraic varieties containi
ng many lines\, planes\, etc. These varieties are very special\, as a typi
cal one from the same family would have no lines at all. This brings up a
natural problem of finding the *maximal* possible number of lines\, planes
\, etc. that can be contained in a member of a fixed family (say\, hypersu
rfaces of a given dimension and degree). In general\, this problem is wide
open\, but I will describe an approach that lets one attack it for a wide
variety of seemingly unrelated families. Finally\, if time permits\, I wi
ll cite a few recent results.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Selçuk Demir (Dokuz Eylül University)
DTSTART:20210521T130000Z
DTEND:20210521T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/17
DESCRIPTION:Title: On Some Entropy Inequalities\nby Selçuk Demir (Dokuz Eylü
l University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nI pl
an to give a survey of an approach of Besenyei and Petz to some entropy in
equalities related to the so-called strong subadditivity. I will discuss a
related conjecture and give a\nreport on its current status. Most of the
talk will be an introduction to this area for mathematicians and will hope
fully be accessible to graduate students of mathematics.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Semra Pamuk (Middle East Technical University)
DTSTART:20210312T130000Z
DTEND:20210312T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/18
DESCRIPTION:Title: Rank conditions for finite group actions on $4$-manifolds\n
by Semra Pamuk (Middle East Technical University) as part of Yeditepe Math
ematics Seminars\n\n\nAbstract\nIn this talk\, I will give some old and ne
w information about the existence of finite group actions on closed\, conn
ected\, orientable $4$-manifolds. In this dimension\, the comparison betwe
en smooth and topological group actions are interesting but our focus will
be on locally linear topological actions. In particular\, we will talk ab
out the following question: Given a closed orientable $4$-manifold $M$\, w
hat is the maximum value of $\\mathrm{rk}(G)$ over all the finite groups $
G$ which act effectively\, locally linearly\, and homologically trivially
on $M$? This is a joint work with Ian Hambleton.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fatma Altunbulak Aksu (Mimar Sinan Fine Arts University)
DTSTART:20210604T130000Z
DTEND:20210604T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/19
DESCRIPTION:Title: Group codes: an application of group algebras to coding theory<
/a>\nby Fatma Altunbulak Aksu (Mimar Sinan Fine Arts University) as part o
f Yeditepe Mathematics Seminars\n\n\nAbstract\nBerman and MacWilliams inde
pendently define group codes as ideals in finite group algebras. Many line
ar codes can be viewed as group codes. For example\, cyclic codes can be c
onsidered as ideals in finite group algebras of cyclic groups and Reed Mul
ler codes over $\\mathbb{F}_p$ can be viewed as ideals in modular group al
gebra of an elementary abelian $p$-group. Group codes have richer algebra
ic structures than linear codes\, for that reason\, considering codes as g
roup codes have many advantages. Algebraic tools in ring theory and charac
ter theory can be used to understand codes via group codes. In this talk I
will give a gentle introduction for group codes and state some problems
and results in the literature. If time permits\, I will state some recent
contributions which are joint work with İpek Tuvay.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Engin Büyükaşık (İzmir Institute of Technology)
DTSTART:20210528T130000Z
DTEND:20210528T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/20
DESCRIPTION:Title: Dual Baer Criterion and R-projectivity of injective modules
\nby Engin Büyükaşık (İzmir Institute of Technology) as part of Yedit
epe Mathematics Seminars\n\n\nAbstract\nLet $R$ be a ring with unity and M
od-$R$ be the category of right $R$-modules. The Baer's Criterion for inje
ctivity states that a right module $M$ is injective iff it is $R$-injectiv
e\, that is for each right ideal $I$ of $R$\, any homomorphism from $I$ i
nto $M$ extends to $R$. Dually\, a right module $P$ is $R$-projective if f
or each right ideal $I$ of $R$ any homomorphism from $M$ into $R/I$ lifts
to $R$. Unlike the case for injectivity\, $R$-projective modules need not
be projective. That is\, the Dual Baer Criterion (DBC\, for short) does n
ot hold over every ring. The rings $R$ for which the DBC holds in Mod-$R$
are called right testing. From [4]\, it is known that right perfect rings
are right testing. In [3]\, Faith stated the characterization of all ri
ght testing rings as an open problem. Recently in [6]\, Trlifaj proved tha
t the problem of characterizing right testing rings is undecidable in ZFC.
\n\nIn this talk\, after summarizing the aforementioned results\, I will m
ention an extend of the notion of $R$-projectivity\, and discuss some pro
blems related to the rings whose injective right modules are $R$-projectiv
e which are partially solved in [1].\n\nReferences\n\n[1] Y. Alagöz and E
. Büyükaşık\, Max-projective modules\, J. Algebra Appl. 20 (2021)\, no
. 6. 2150095.\n\n[2] H. Alhilali\, Y. Ibrahim\, G. Puninski\, and M. Yousi
f\, When R is a testing module for projectivity? J. Algebra 484 (2017)\, 1
98-206.\n\n[3] C. Faith\, Algebra. II\, Springer-Verlag\, Berlin-New York\
, 1976. Ring theory\, Grundlehren der Mathematischen Wissenschaften\, No.
191.\n[4] F .L. Sandomierski\, Relative injectivity and projectivity\, 196
4. Thesis (Ph.D.) The Pennsylvania\nState University.\n\n[5] J. Trlifaj\,
Whitehead test modules\, Trans. Amer. Math. Soc. 348 (1996)\, no. 4\, 1521
-1554.\n\n[6] J. Trlifaj\, Faith’s problem on R-projectivity is undecida
ble\, Proc. Amer. Math. Soc. 147 (2019)\,\nno. 2\, 497-504.\n\n[7] J. Trli
faj\, The dual Baer Criterion for non-perfect rings\, Forum Math. 32 (2020
)\, no. 3\, 663-672.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alp Bassa (Boğaziçi University)
DTSTART:20210409T130000Z
DTEND:20210409T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/21
DESCRIPTION:Title: Rational points on curves over finite fields and their asymptot
ic\nby Alp Bassa (Boğaziçi University) as part of Yeditepe Mathemati
cs Seminars\n\n\nAbstract\nCurves over finite fields with many rational po
ints have been of interest for both theoretical reasons and for applicatio
ns. To obtain such curves with large genus various methods have been emplo
yed in the past. One such method is by means of explicit recursive equatio
ns and will be the emphasis of this talk. The recursive nature of these to
wers makes them very special and in fact all good examples have been shown
to have a modular interpretation of some sort. In this talk I will try to
give an overview of the landscape of explicit recursive towers and their
modularity.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Müge Kanuni Er (Düzce University)
DTSTART:20210416T100000Z
DTEND:20210416T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/22
DESCRIPTION:Title: Socle of Incidence Rings\nby Müge Kanuni Er (Düzce Univer
sity) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nIn his semin
al paper of 1964\, "On the foundations of combinatorial theory I: Theory o
f Möbius Functions" Gian-Carlo Rota defined an incidence ring as a tool f
or solving combinatorial problems. Incidence ring is a specific ring of fu
nctions defined on the ordered pairs of a given partially ordered set to a
given ring. Möbius function is an element of an incidence ring\, besides
with the appropriate choice of the partially ordered set\, Möbius functi
on of this incidence algebra coincides with the well-known Möbius functio
n of number theory. A product of copies of a ring and upper triangular mat
rices are typical examples of incidence algebras. \n\nThe investigation of
a ring is usually enriched by understanding specialtypes of ideals of it\
, such as the Jacobson radical\, the prime radical\, the socle\,the singul
ar ideal\, the center\, etc. Although incidence rings have been an object
of study for a few decades\, there does not seem to be any results in the
literature on the socle of incidence rings.\n\nIn this talk\, we will be r
estricting the left socle of an incidence ring between two sets.More expli
citly\, we compute the socle of an incidence ring I(X\,R) under some assu
mptions on the ring R and/or the partially ordered set X. \n\n(This joint
work with Özkay Özkan- https://doi.org/10.15672/hujms.684042 )\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Benjamin Matschke (Boston University)
DTSTART:20210319T150000Z
DTEND:20210319T160000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/23
DESCRIPTION:Title: Proofs by example\nby Benjamin Matschke (Boston University)
as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nWe study the proo
f method "proof by example" in which a general statement can be proved by
verifying it for a single example. This strategy can indeed work if the st
atement in question is an algebraic identity and the example is "generic".
This talk addresses the problem of constructing a practical example\, whi
ch is sufficiently generic\, for which the statement can be verified effic
iently\, and which allows for a numerical margin of error.\n\nOur method i
s based on diophantine geometry\, in particular an arithmetic Bezout theor
em\, an arithmetic Nullstellensatz\, and a new effective Liouville-Lojasie
wicz type inequality for algebraic varieties. As an application we discuss
theorems from plane geometry and how to\nprove them by example.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oğuz Şavk (Boğaziçi University)
DTSTART:20210305T130000Z
DTEND:20210305T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/24
DESCRIPTION:Title: Classical and New Plumbings Bounding Contractible Manifolds and
Homology Balls\nby Oğuz Şavk (Boğaziçi University) as part of Yed
itepe Mathematics Seminars\n\n\nAbstract\nA central problem in low-dimensi
onal topology asks which\nhomology 3-spheres bound contractible 4-manifold
s and homology 4-balls.\nIn this talk\, we address this problem for plumbe
d 3-manifolds and we\npresent the classical and new results together. Our
approach is based on\nMazur’s famous argument which provides a unificati
on of all results in a\nfairly simple way.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Berrin Şentürk (TED University)
DTSTART:20210430T130000Z
DTEND:20210430T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/25
DESCRIPTION:Title: Free Group Actions on Product of 3 Spheres\nby Berrin Şent
ürk (TED University) as part of Yeditepe Mathematics Seminars\n\n\nAbstra
ct\nA long-standing Rank Conjecture states that if an elementary abelian $
p$-group acts freely on a product of spheres\, then the rank of the group
is at most the number of spheres in the product. We will discuss the algeb
raic version of the Rank Conjecture given by Carlsson for a differential g
raded module $M$ over a polynomial ring. We will state a stronger conjectu
re concerning varieties of square-zero upper triangular matrices correspon
ding to the differentials of certain modules. By the work on free flags in
$M$ introduced by Avramov\, Buchweitz\, and Iyengar\, we will obtain some
restriction on the rank of submodules of these matrices. By this argument
we will show that $(\\mathbb{Z}/2\\mathbb{Z})^4$ cannot act freely on pro
duct of $3$ spheres of any dimensions.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Uğur Yiğit (İstanbul Medeniyet University)
DTSTART:20210402T130000Z
DTEND:20210402T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/26
DESCRIPTION:Title: $C_2$-Equivariant EHP Sequences\nby Uğur Yiğit (İstanbul
Medeniyet University) as part of Yeditepe Mathematics Seminars\n\n\nAbstr
act\nTo determine the homotopy groups $\\pi_n(S^k)$ of spheres is a centra
l problem in homotopy\ntheory. One of the main tools for calculations in t
he classical unstable homotopy theory is\nthe EHP sequence. In this talk\,
we give the generalizations of the EHP sequence in the classical homotopy
theory to the $C_2$-equivariant case.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ayhan Günaydin (Boğaziçi University)
DTSTART:20210611T130000Z
DTEND:20210611T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/27
DESCRIPTION:Title: Model Theory of Beatty Sequences\nby Ayhan Günaydin (Boğa
ziçi University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\n
The Beatty Sequence generated by an irrational r>1 is ([nr] : n>0)\, where
[c] denotes the integer part of a real number c. A well-known property of
this sequence is that "any pattern that appears once has to appear infini
tely many times\; moreover we may determine when a pattern appears next ti
me with a small error". After explaining what this means\, we will present
the proof of a strengthening of it. Our proof depends on the model theore
tic study of the sequence and all the necessary background will be overvie
wed. (This is a joint work with Melissa Özsahakyan.)\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Ünlü (Yeditepe University)
DTSTART:20211001T130000Z
DTEND:20211001T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/28
DESCRIPTION:Title: The impossibility of the angle trisection by straightedge and c
ompass revisited\nby Yusuf Ünlü (Yeditepe University) as part of Yed
itepe Mathematics Seminars\n\n\nAbstract\nIt is well known that the angle
trisection or doubling the cube is impossible by using only ruler and comp
ass. The usual algebraic proof uses the fact that if a real number $\\xi$
is constructible using only ruler and compass then there is a tower of fie
lds\n$$\\mathbb Q= F_0 \\subset F_1 \\subset \\cdots \\subset F_n$$\nsu
ch that if $n \\geq 1$\, then $F_i = F_{i-1}(u_i)$ where $u_i\\notin F_{i-
1}$ but $u_i^2\\in F_{i-1}$ and $\\xi \\in F_n$. Hence $2^m = [F_n : \\ma
thbb Q]$ for some $m \\in \\mathbb N$. This shows that $$2^m = [F_n : \\ma
thbb Q]= [F_n : \\mathbb Q(\\xi)][\\mathbb Q(\\xi) : \\mathbb Q]$$ \nSo\,
if the minimal polynomial of $\\xi$ in $\\mathbb Q(x)$ is of odd degree\,
then $\\xi$ is\nnot constructible by only ruler and compass. Moreover\, t
he minimal\npolynomial of $\\cos 20^\\circ$ has degree $3$. So it is impos
sible to trisect $60^\\circ$ by\nusing only ruler and compass.\n\nHowever\
, this proof requires the fundamentals of vector spaces. In this talk\, we
wíll tweak the last part of the proof to avoid vector spaces.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cihan Okay (Bilkent University)
DTSTART:20211105T130000Z
DTEND:20211105T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/29
DESCRIPTION:Title: Homotopy classification of operator solutions of linear systems
\nby Cihan Okay (Bilkent University) as part of Yeditepe Mathematics S
eminars\n\n\nAbstract\nLinear systems of equations over a finite field pla
y an important role in quantum information theory. Instead of looking for
solutions over the base field one can look for solutions (in a certain sen
se) over the unitary group\, which are called operator solutions. The data
of this system of equations can be expressed using a hypergraph and the o
perator solutions can be studied from a topological point of view by consi
dering certain topological realizations of these hypergraphs. In this talk
I will describe how homotopical methods provide a way to classify operato
r solutions of linear systems. Our basic approach is to interpret operator
solutions as maps from a topological realization of the hypergraph to a c
ertain classifying space first introduced by Adem-Cohen-Torres Giese.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oktay Pashaev (İzmir Institute of Technology)
DTSTART:20211008T130000Z
DTEND:20211008T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/30
DESCRIPTION:Title: Quantum Calculus of Fibonacci Divisors applied to Classical Met
hod of Images and Quantum Computational States\nby Oktay Pashaev (İz
mir Institute of Technology) as part of Yeditepe Mathematics Seminars\n\n\
nAbstract\nStarting from divisibility problem for Fibonacci numbers\, we i
ntroduce integer Fibonacci divisors\, conjugate to $F_k$\, related hierarc
hy of Golden derivatives in powers of the Golden Ratio and develop corresp
onding quantum calculus. By the set of translation operators\, we find the
hierarchy of Golden binomials and related Golden analytic functions. In t
he limit $k \\to 0\,$ these functions reduce to classical holomorphic func
tions and quantum calculus of Fibonacci divisors to the usual one. The hie
rarchy of Golden periodic functions appearing in this calculus\, we relate
with classical method of images in planar hydrodynamics (electrostatics).
Several applications of the calculus to quantum deformed algebras and qua
ntum computation and information theory are discussed. In particular\, we
show that for repeated consecutive duplicated qubit states\, probabilities
are determined by Fibonacci numbers. We generalize these results for dire
ct product of multiple qubit states and arbitrary position of repeated sta
tes. The calculations are based on structure of Fibonacci trees in space o
f qubit states\, growing in the left and in the right directions\, number
of branches and allowed paths on the trees.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sefa Feza Arslan (Mimar Sinan Fine Arts University)
DTSTART:20211210T130000Z
DTEND:20211210T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/32
DESCRIPTION:Title: Numerical Semigroups\, Apery table and Hilbert functions\nb
y Sefa Feza Arslan (Mimar Sinan Fine Arts University) as part of Yeditepe
Mathematics Seminars\n\n\nAbstract\nIn this talk\, I will first introduce
the concept of Apery table of a numerical semigroup introduced by Cortedel
las and Zarzuela (Tangent cones of numerical semigroup rings. Contemp. Mat
h. 502\, 45–58 (2009)). After presenting some open problems about Hilber
t functions of local rings\, I will give some partial results in the case
of local rings associated to numerical semigroups.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gülin Ercan (Middle East Technical University)
DTSTART:20211217T130000Z
DTEND:20211217T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/34
DESCRIPTION:Title: Good Action\nby Gülin Ercan (Middle East Technical Univers
ity) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nLet $G$ be a
group acted on by a group $A$ by automorphisms. The nature of this\naction
is very restrictive and hence informative about the structure of $G$. We
have\nbeen carrying on research in this area\, especially on length type p
roblems\, in several\ncollaborated works over the years. The action is sai
d to be coprime if $G$ and $A$ have\ncoprime orders. The existence of nice
conditions which are valid in this case made\nit almost traditional to as
sume that the action is coprime. After many attacks to a\nlongstanding non
coprime conjecture we have recently introduced the concept of a\ngood acti
on of $A$ on $G$ in a joint work with Güloğlu and Jabara. We say the act
ion\nis “good” if $H = [H\, B]C_H(B)$ for every subgroup $B$ of $A$ an
d for every $B$-invariant\nsubgroup $H$ of $G$. It can be regarded as a ge
neralization of the coprime action due\nto the fact that every coprime act
ion is good and there are noncoprime actions\nwhich are good. It is expect
ed that this concept may help to understand the real\ndifficulties in stud
ying a noncoprime action. We have achieved extending several\ncoprime resu
lts to good action case. With this talk I aim to present a review of\nour
results and discuss the main difficulties that arise in the study of a non
coprime\ngood action.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sibel Şahin (Mimar Sinan Fine Arts University)
DTSTART:20211015T130000Z
DTEND:20211015T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/35
DESCRIPTION:Title: de Branges-Rovnyak spaces $H(b)$ from unit disc to unit ball of
$\\mathbb C^n$\nby Sibel Şahin (Mimar Sinan Fine Arts University) as
part of Yeditepe Mathematics Seminars\n\n\nAbstract\nIn this talk we will
consider a special subclass of the Hardy-Hilbert space $H^2$ namely de Br
anges-Rovnyak spaces $H(b)$\, first with an introduction of model spaces i
n the unit disc and then in the setting of the unit ball of $\\mathbb C^n$
. One of the main problems in the study of $H(b)$ functions is their integ
ral representation and in this talk we will see how we can represent these
classes through the Clark measure on $S^n$ associated with $b$. In the se
cond part we will give a characterization of admissible boundary limits in
relation with finite angular derivatives and we will see the interplay be
tween Clark measures and angular derivatives showing that Clark measure as
sociated with $b$ has an atom at a boundary point if and only if $b$ has f
inite angular derivative at the same point. More detailed analysis of the
concepts mentioned in this talk can be found in the following study.\n\n\
n[1] Şahin\, S.\, Angular Derivatives and Boundary Values of $H(b)$ Space
s of Unit Ball of $\\mathbb C^n$\, Complex Variables and Elliptic Equation
s\, Volume 66\, Issue 2\, pp:226-237\, (2021).\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nadia Romero (Universidad de Guanajuato)
DTSTART:20211119T150000Z
DTEND:20211119T160000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/36
DESCRIPTION:Title: Operations on the Frobenius-Wielandt morphism\nby Nadia Rom
ero (Universidad de Guanajuato) as part of Yeditepe Mathematics Seminars\n
\n\nAbstract\nIn 1992\, Dress\, Siebeneicher and Yoshida introduced the Fr
obenius-Wielandt morphism (FW morphism)\, defined from the Burnside ring o
f a cyclic group C to the Burnside ring of a finite group G of order |C|.
A remark in their article indicates that their intention was "to give a pr
ecise conceptual interpretation of the observation that many elementary gr
oup-theoretic results can be derived from the fact that various invariants
of an arbitrary group are closely related to the same invariant evaluated
for the cyclic group C". Among other properties\, they investigated the r
elation of the FW morphism with the operations of restriction\, induction\
, inflation and fixed points. In this talk we will see what can be said ab
out the relation of the FW morphism with other operations related to the B
urnside ring\, especifically: tensor induction and deflation.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Orendain (Universidad Nacional Autónoma de México)
DTSTART:20220404T163000Z
DTEND:20220404T173000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/37
DESCRIPTION:Title: End-indexings and lifts to framed bicategories\nby Juan Ore
ndain (Universidad Nacional Autónoma de México) as part of Yeditepe Math
ematics Seminars\n\n\nAbstract\nFramed bicategories are double categories
satisfying cerain fibrancy conditions. Many structures naturally organize
into framed bicategories\, e.g. relations\, profunctors\, adjoints\, open
Petri nets\, polynomials functors\, polynomial comonoids\, structured cosp
ans\, etc. Symmetric monoidal structures on framed bicategories descend to
symmetric monoidal structures on horizontal bicategories. The axioms defi
ning symmetric monoidal double categories are considerably more tractible
than those defining symmetric monoidal bicategories. It is thus convenient
to study ways of lifting a given bicategory into a framed bicategory alon
g an appropriate category of vertical morphisms. Solutions to the problem
of lifting bicategories to double categories have classically being useful
in expressing Kelly and Street's mates correspondence and in proving the
2-dimensional Seifert-van Kampen theorem of Brown et. al.\, amongst many o
ther applications. We consider lifting problems in their full generality.\
n\nGlobularly generated double categories are minimal solutions to lifting
problems of bicategories into double categories along given categories of
vertical arrows. Globularly generated double categories form a coreflecti
ve sub-2-category of general double categories. This\, together with an an
alysis of the internal structure of globularly generated double categories
yields a numerical invariant on general double categories. We call this i
nvariant the length. The length of a double category $C$ measures the comp
lexity of mixed compositions of globular and horizontal identity squares o
f $C$ and thus provides a measure of complexity for lifting problems of bi
categories into $C$. It has long being conjectured by the author that fram
ed bicategories are of length 1.\n\nI will explain recent results on the t
heory of globularly generated double categories\, the length invariant\, a
nd the theory of framed bicategories\, making use of certain types of inde
xings and opindexings on decorated bicategories.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kağan Kurşungöz (Sabancı University)
DTSTART:20220307T113000Z
DTEND:20220307T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/41
DESCRIPTION:Title: Capparelli's Identities and the Kanade-Russell Conjectures\
nby Kağan Kurşungöz (Sabancı University) as part of Yeditepe Mathemati
cs Seminars\n\n\nAbstract\nWe will review the basics of integer partitions
\, then we will give a very rough\, somewhat subjective\, classification o
f partition identities. We will impress on the impact of Capparelli's ide
ntities on integer partition theory\, and talk about Kanade-Russell conjec
tures as time allows.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sultan Eylem Toksoy (Hacettepe University)
DTSTART:20220328T113000Z
DTEND:20220328T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/42
DESCRIPTION:Title: On some generalizations from Module Categories to Grothendieck
Categories by using Purity\nby Sultan Eylem Toksoy (Hacettepe Universi
ty) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nThe notion of
pure subgroups were first investigated by Prufer in [9]. Purity has utmost
importance in abelian group theory because it makes possible to use the m
ethods of relative homological algebra as there are enough pure-injective
and enough pure-projective groups. The purity concept was extended to modu
les over arbitrary rings by Cohn [3]\, Bourbaki [1]\, Butler and Horrocks
[2] and Walker [11]. Stenström generalized the notion of purity to an abe
lian category with a (projective) generator in [10]. The notions of Rickar
t and dual Rickart were introduced and studied for modules by Lee\, Rizvi
and Roman [6\, 7\, 8]. Rickart and dual Rickart modules have been generali
zed to abelian categories by Crivei\, Kör and Olteanu [4\, 5]. In this wo
rk\, (dual) purely Rickart objects are introduced as generalizations of (d
ual) Rickart objects in Gröthendieck categories. Examples showing the rel
ations between (dual) relative Rickart objects and (dual) relative purely
Rickart objects are given. It is shown that in a spectral category (dual)
relative purely Rickart objects coincide with (dual) relative Rickart obje
cts. (Co)products of (dual) relative purely Rickart objects are studied. C
lasses all of whose objects are (dual) relative purely Rickart are identif
ied. Applications to comodule categories are given.\n\nReferences\n\n[1] N
. Bourbaki\, Elements of Mathematics\, Commutative Algebra\, Addison-Wesle
y Publishing Company\, Advanced Book Program\, Reading Massachusetts\, 197
2. Originally published as: Elements De Mathematique\, Algebre Commutative
\, Hermann\, Paris\, 1969.\n\n[2] M. C. R. Butler and G. Horrocks\, Classe
s of Extensions and Resolutions\, Phil. Trans. Royal Soc. of London\, Seri
es A 254 (1961)\, 155–222.\n\n[3] P. M. Cohn\, On the Free Product of As
sociative Rings\, Mathematische Zeitschrift 71 (1959)\, 380–398.\n\n[4]
S. Crivei and A. Kör\, Rickart and Dual Rickart Objects in Abelian Catego
ries\, Appl Categor Struct 24 (2016)\, 797–824.\n\n[5] S. Crivei and G.
Olteanu\, Rickart and Dual Rickart Objects in Abelian Categories: Transfer
via Functors\, Appl Categor Struct 26 (2018)\, 681–698.\n\n[6] G. Lee\,
S. T. Rizvi and C. S. Roman\, Rickart Modules\, Comm. Algebra 38 (2010)\,
4005–4027.\n\n[7] G. Lee\, S. T. Rizvi and C. S. Roman\, Dual Rickart M
odules\, Comm. Algebra 39 (2011)\, 4036–4058. \n\n[8] G. Lee\, S. T. Riz
vi and C. S. Roman\, Direct Sums of Rickart Modules\, J. Algebra 353 (2012
)\, 62–78.\n\n[9] H. Prüfer\, Untersuchungen über die Zerlegbarkeit d
er abzaehlbaren prim aeren Abelschen Gruppen\, Mathematische Zeitschrift 1
7 (1923)\, 35–61.\n\n\n[10] B. T. Stenström\, Pure submodules\, Arkiv F
ör Matematik 7 (10) (1966)\, 159–171.\n\n[11] C. L. Walker\, Relative H
omological Algebra and Abelian Groups\, Illinois J. Math. 10 (1966)\, 186
–209\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Haldun Özgür Bayındır (City\, University of London)
DTSTART:20220411T113000Z
DTEND:20220411T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/43
DESCRIPTION:Title: Adjoining roots to ring spectra and algebraic K-theory\nby
Haldun Özgür Bayındır (City\, University of London) as part of Yeditep
e Mathematics Seminars\n\n\nAbstract\nThe category of spectra captures an
important part of the complexity of topological spaces while providing gen
eralizations of many important notions in homological algebra. \n\nIn this
work\, we develop a new method to adjoin roots to ring spectra and show t
hat this process results in interesting splittings in algebraic K-theory.\
n\nIn the first part of my talk\, I will provide motivation for algebraic
K-theory and highly structured ring spectra. After this\, I will discuss t
race methods\, a program that provides computational tools for algebraic K
-theory\, and introduce our results.\n\nThis is a joint work in progress w
ith Tasos Moulinos and Christian Ausoni.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Esma Dirican Erdal (Yeditepe University)
DTSTART:20220321T113000Z
DTEND:20220321T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/45
DESCRIPTION:Title: On Reidemeister Torsion of Closed Stably Parallelizable Manifo
lds\nby Esma Dirican Erdal (Yeditepe University) as part of Yeditepe M
athematics Seminars\n\n\nAbstract\nLet $M$ be a closed orientable $(n-2)$-
connected $2n$-dimensional stably parallelizable manifold. Such an $M$ ad
mits a connected sum decomposition into simpler submanifolds. In this ta
lk\, by using such decompositions\, we will give multiplicative gluing fo
rmulas that express the Reidemeister torsion of $M$ with untwisted real co
efficients in terms of Reidemeister torsions of its building blocks. This
is a joint work with Yaşar Sözen.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valery Romanovski (University of Maribor)
DTSTART:20220518T113000Z
DTEND:20220518T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/46
DESCRIPTION:Title: Integrability and limit cycles in polynomial systems of ODE's<
/a>\nby Valery Romanovski (University of Maribor) as part of Yeditepe Mat
hematics Seminars\n\n\nAbstract\nWe discuss two problems related to the th
eory of polynomial plane differential systems\, that is\, systems of the
form \n \\begin{equation} \\label{1}\n \\frac{dx}{dt}=P_{n}(x\,y)\, \\
\\ \\ \n \\frac{dy}{dt}=Q_{n}(x\,y)\,\n \\end{equation}
\nwhere $P_{n}(x\,y)\, Q_{
n}(x\,y)$ are polynomials of degree $n$\, $x$ and $y$ are real unknown fun
ctions.\n \nThe first one is the problem of local integrability\, that is
\, the problem of finding local analytic integrals in a neighborhood of s
ingular points of system (1). We present a computational approach to fin
d integrable systems within given parametric families of systems and desc
ribe some mechanisms of integrability. \n \nThe second problem is call
ed the cyclicity problem\, or the local 16th Hilbert problem\, and is rel
ated to the estimation of the number of limit cycles arising in system (1)
after perturbations of integrable systems. The approach is algorithmic an
d is based on algorithms of computational commutative algebra relying on
the Groebner bases theory.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:İpek Tuvay (Mimar Sinan Fine Arts University)
DTSTART:20220425T113000Z
DTEND:20220425T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/47
DESCRIPTION:Title: On minimal abelian group codes\nby İpek Tuvay (Mimar Sinan
Fine Arts University) as part of Yeditepe Mathematics Seminars\n\n\nAbstr
act\nGroup codes are special types of linear codes that carry more algebra
ic structure. They can be seen as ideals of group algebras and because of
this\, representation theoretic techniques help us to understand these cod
es better. When the group algebra is semisimple\, any group code is a dire
ct sum of minimal ones. \n\nIn this talk\, first group codes will be intro
duced together with different types of examples. Then an equivalence relat
ion among the minimal codes will be introduced and open problems concernin
g this notion will be stated. Afterwards\, recent contributions to the sol
ution of these open problems will be given. This is a joint work with Fatm
a Altunbulak Aksu.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mehmet Akif Erdal (Yeditepe University)
DTSTART:20220523T113000Z
DTEND:20220523T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/49
DESCRIPTION:Title: Vector bundles that appear as normal bundles of manifolds\n
by Mehmet Akif Erdal (Yeditepe University) as part of Yeditepe Mathematics
Seminars\n\n\nAbstract\nGiven a Poincaré complex $X$\, a vector bundle $
\\xi$ over $X$ is said to be realized by the normal bundle of a manifold $
M$\, if $\\xi$ is pulled back from the normal bundle of $M$ along a homoto
py equivalence $X\\rightarrow M$. The problem of determining such bundles
over an arbitrary Poincaré complex is a difficult problem and is related
to classical problems of surgery theory. In this talk\, we will discuss so
me methods of approaching this problem and talk about solutions for certai
n cases of $X$. In particular\, we will discuss conditions on bundles over
$X$ that guarantee they are realized by normal bundles of manifolds\, for
$X$ belonging to a certain class of homology spheres.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikolai Andreev (Steklov Mathematical Institute of RAS)
DTSTART:20220702T103000Z
DTEND:20220702T113000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/50
DESCRIPTION:Title: Mathematical Essence\nby Nikolai Andreev (Steklov Mathemati
cal Institute of RAS) as part of Yeditepe Mathematics Seminars\n\nLecture
held in Mathematics Department Seminar Room.\n\nAbstract\nOn the interacti
ve lecture we will discuss the mathematical essence of the\ngreatest achie
vements of civilization and the mathematical basis\nhabitual\, everyday t
hings and phenomena. We will use materials of the\nbook "Mathematical e
ssence" (http://book.etudes.ru/) authors of\nwhich are leading mathem
aticians and films from the project "Mathematical\nEtudes" (http://ww
w.etudes.ru/).\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kamuran Saygılı (İstanbul University)
DTSTART:20221014T113000Z
DTEND:20221014T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/51
DESCRIPTION:Title: A Course: Introduction to Mathematical Optics I\nby Kamuran
Saygılı (İstanbul University) as part of Yeditepe Mathematics Seminars
\n\n\nAbstract\nOutline of a course: Introduction to Mathematical Optics.\
n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kamuran Saygılı (İstanbul University)
DTSTART:20221021T113000Z
DTEND:20221021T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/53
DESCRIPTION:Title: A Course: Introduction to Mathematical Optics II\nby Kamura
n Saygılı (İstanbul University) as part of Yeditepe Mathematics Seminar
s\n\n\nAbstract\nOutline of a course: Introduction to Mathematical Optics.
\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Segovia González (Universidad Nacional Autónoma de Méxic
o)
DTSTART:20221028T130000Z
DTEND:20221028T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/55
DESCRIPTION:Title: Extension of free actions over surfaces\nby Carlos Segovia
González (Universidad Nacional Autónoma de México) as part of Yeditepe
Mathematics Seminars\n\n\nAbstract\nOriented\, nonoriented and unitary bor
dism have certain module structures. We are interested in the unitary case
which is a free module over the integers with even degrees. In the case o
f equivariant unitary bordism for a compact Lie group\, it has been shown
that for certain cases\, we have a structure of free module (with respect
to the usual unitary bordism) with generators in even degrees. Just to men
tion\, Landweber proved the case of cyclic groups\, Stong-Ossa the abelian
groups\, Löffer-Comezaña for compact abelian Lie groups and there are s
ome proofs for metacyclic groups. The general case is known as the unitary
evenness conjecture (UEC). This conjecture will imply that in equivariant
bordism there is not torsion. A particular case will be that all free act
ion of a finite group over a compact oriented surface “always” extends
to a non-necessarily free action over a 3-manifold. In this talk we will
see a counterexample that this is not always the case\, which gives a coun
terexample of (UEC). A complete obstruction is given by the quotient of th
e 2-homology H_2(G) by the toral classes\, known as the Bogomolov multipli
er. The firs counterexample published is a group of order 3^5.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laurence John Barker (Bilkent University)
DTSTART:20221209T113000Z
DTEND:20221209T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/56
DESCRIPTION:Title: The Puig category of a block and conjectural isomorphism invari
ance of the multiplicities of the objects\nby Laurence John Barker (Bi
lkent University) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\n
A modular group algebra decomposes as a sum of algebras called block algeb
ras. The group acts as automorphisms on each block algebra. Reducing $p$-l
ocally\, we pass to a smaller algebra called an almost-source algebra\, up
on which a p-subgroup called the defect group acts as automorphisms. Three
measures of the complexity of the block are\,firstly\, the defect group i
tself\, secondly a finite category called the fusion system\,thirdly a som
ewhat larger finite category called the Puig category. Each object of the
Puig category comes with an associated multiplicity. We conjecture that th
ose multiplicities are invariant under the action of the fusion system. Th
e conjecture has implications concerning the action of the defect group on
a permuted basis of the almost-source algebra. By Clifford theory\, the c
onjecture holds when the given group is p-solvable. This work is joint wit
h Matthew Gelvin.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pelin Ayşe Gökgöz (Yeditepe University)
DTSTART:20221202T113000Z
DTEND:20221202T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/57
DESCRIPTION:Title: Schwarz Problem in the Complex Plane\nby Pelin Ayşe Gökg
öz (Yeditepe University) as part of Yeditepe Mathematics Seminars\n\n\nAb
stract\nIn this talk\, we investigate the Schwarz problem in a ring domain
. We start with derivation of\nthe unique solution of the Schwarz problem
for inhomogeneous Cauchy-Riemann equations and\ngeneralized Beltrami equat
ions. Next\, we extend the discussion to higher-order Cauchy-Riemann\nequa
tions and higher-order linear equations employing the properties of higher
-order operators.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Barış Kartal (University of Edinburgh)
DTSTART:20221216T113000Z
DTEND:20221216T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/58
DESCRIPTION:Title: Frobenius operators in symplectic topology\nby Yusuf Barı
ş Kartal (University of Edinburgh) as part of Yeditepe Mathematics Semina
rs\n\n\nAbstract\nGiven prime p\, one can define Frobenius operators on th
e commutative rings of characteristic p. This notion has generalizations i
n a larger class of rings and even in topological spaces and spectra. Spec
tra with circle actions and Frobenius operators are called cyclotomic spec
tra. A simple example is the free loop space. Major examples arise in alge
braic and arithmetic geometry\, as topological Hochschild homology of ring
s and categories\, and many applications to these fields are found. By mir
ror symmetry\, it is natural to expect the cyclotomic spectra to arise in
symplectic topology. In this talk\, we will explain how to obtain cyclotom
ic spectra using holomorphic cylinders in symplectic manifolds\, i.e. by u
sing Hamiltonian Floer theory. Joint work in progress with Laurent Cote.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Burcu Silindir Yantır (Dokuz Eylül University)
DTSTART:20230317T113000Z
DTEND:20230317T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/59
DESCRIPTION:Title: Generalized discrete polynomials and applications\nby Burcu
Silindir Yantır (Dokuz Eylül University) as part of Yeditepe Mathematic
s Seminars\n\n\nAbstract\nAlthough the calculus and the theory of differen
ce/differential equations have been deeply analyzed since the discovery of
time scales\, the study on a general time scale may have deficiencies and
inapplicabilities even in some elementary subjects such as polynomials\,
exponential functions\, Taylor series. To overcome these deficiencies\, in
this talk\, we present two approaches which unify and extend discrete tim
e scales. First approach is based on the study of a special time scale\, n
amely $(q\,h)$-time scale. We briefly introduce the calculus on delta and
nabla $(q\,h)$-time scales. As an application\, we focus on $(q\,h)$-analo
gue of Bessel equation and Bessel function which reduce $h$-\, $q$- and or
dinary Bessel equations and functions under proper limits. Furthermore\, w
e present a second approach which is based on the construction of a new ti
me scale\, namely $\\alpha$-time scale. For this purpose\, we offer a weig
hted jump operator $\\alpha$\, which generates the $\\alpha$-time scale\,
$\\alpha$-derivative and $\\alpha$-polynomials.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Ünlü (Yeditepe University)
DTSTART:20221118T113000Z
DTEND:20221118T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/60
DESCRIPTION:Title: Compactifications of a Tychonoff space\nby Yusuf Ünlü (Ye
ditepe University) as part of Yeditepe Mathematics Seminars\n\nAbstract: T
BA\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:İlhan İkeda (Boğaziçi Üniversity)
DTSTART:20230609T093000Z
DTEND:20230609T103000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/61
DESCRIPTION:Title: Dictionary of Gröthendieck and automorphic representations
\nby İlhan İkeda (Boğaziçi Üniversity) as part of Yeditepe Mathematic
s Seminars\n\n\nAbstract\nIn the first part of our talk\, we shall review
Gröthendieck's "function-sheaf dictionary"\, and in the second part\, we
shall discuss how this dictionary is used in\nthe Langlands reciprocity pr
inciple.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atabey Kaygun (İstanbul Technical University)
DTSTART:20230407T113000Z
DTEND:20230407T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/63
DESCRIPTION:Title: Extending Dold-Kan Theorem to Crossed Simplicial Groups\nby
Atabey Kaygun (İstanbul Technical University) as part of Yeditepe Mathem
atics Seminars\n\n\nAbstract\nThe Dold-Kan Theorem is a statement about th
e equivalence between the category of simplicial objects and the category
of chain complexes over an abelian category\, after certain natural locali
zations. This equivalence is a Quillen equivalence\, with different restri
cted versions of it appearing in literature. In this talk\, we will explor
e an extension to the Dold-Kan equivalence by replacing the simplicial cat
egory with a crossed simplicial group. Crossed simplicial groups are obtai
ned from the simplicial category through a bicrossed product between the s
implicial category and certain collections of (finite) groups. Connes' cyc
lic category being an example of this construction. While previous attempt
s to extend the Dold-Kan to the Connes' cyclic category and beyond involve
d constructing artificial categories in place of the category of dg-object
s over an abelian category\, we will pursue a new approach in this talk. S
pecifically\, we will show that the Dold-Kan result can be reformulated us
ing certain induction and restriction functors\, providing a clear path fo
r a natural extension of the Dold-Kan to crossed simplicial groups when th
e groups used are all finite. This is an ongoing joint research project wi
th my PhD student\, Haydar Can Kaya.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yusuf Civan (Süleyman Demirel Üniversitesi)
DTSTART:20230505T113000Z
DTEND:20230505T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/64
DESCRIPTION:Title: Nerves\, minors and coloring of graphs\nby Yusuf Civan (Sü
leyman Demirel Üniversitesi) as part of Yeditepe Mathematics Seminars\n\n
Lecture held in Yeditepe Math. Department Seminar Room.\n\nAbstract\nA rec
ent work of Holmsen et al. provides a topological method for detecting cli
que minors in graphs. They conjecture that the homological dimension of (n
erves of) connected covers completely detects clique minors. I will explai
n in detail how this approach works\, and show that if it is true\, their
conjecture is almost equivalent to the Hadwiger conjecture. I will provide
a counterpart of this conjecture in the language of bipartite graphs\, an
d verify a relaxed version.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hasan Gümral (Yeditepe University)
DTSTART:20230512T113000Z
DTEND:20230512T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/65
DESCRIPTION:Title: Tulczyjew Symplectic Spaces for Displacement and Canonical Mapp
ings\nby Hasan Gümral (Yeditepe University) as part of Yeditepe Mathe
matics Seminars\n\n\nAbstract\nGiven a finite dimensional manifold $Q$\, t
he cotangent bundle $(T^* Q\, \\omega)$ is symplectic. Let $M = \\{\\xi :
T ^*Q \\to Q \\}$ and $G =\\{ \\phi : T^*Q\\to T^*Q | \\phi^*\\omega =\\o
mega\\} $ be manifolds of displacement and canonical mappings\, respective
ly. $G$ is a Lie group and bundles over $G$ admit global trivializations.
The embedding $G\\hookrightarrow T^*M$ is Lagrangian\, though\, not with c
anonical two-form. It follows that the Tulczyjew symplectic spaces $TT^* M
$ and $T T^*G$ are fiberwise isomorphic. This result is key to establish
ing relations among different formulations of plasma dynamics in the Tulcz
yjew's geometric framework for Legendre transformation.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mehmet Akif Erdal (Yeditepe Univesity)
DTSTART:20190315T113000Z
DTEND:20190315T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/66
DESCRIPTION:Title: Equivariant model structures via orbits\nby Mehmet Akif Erd
al (Yeditepe Univesity) as part of Yeditepe Mathematics Seminars\n\nLectur
e held in Seminar Room.\n\nAbstract\nFor a given group $G$ the category of
$G$-spaces and $G$-equivariant maps admits a model structure in which the
weak equivalences and fibrations are defined as $G$-maps that induce weak
equivalences and fibrations on $H$-fixed point spaces for every $H \\leq
G$. In this model category the fibrant-cofibrant objects are $G$-$CW$-comp
lexes. A weak equivalence between such objects is a $G$-homotopy equivalen
ce\; and thus\, induces weak equivalences on $H$-orbits for every $H \\leq
G$. The converse\, however\, is not true. It is natural to ask what is ne
eded for $X\,Y$ so that maps $f:X\\to Y$ inducing weak equivalences on $H$
-orbits also induce weak equivalences on $H$-fixed point spaces. To provid
e an answer\, we construct a new model structure on the category of $G$-sp
aces in which the weak equivalences and cofibrations are defined as maps i
nducing weak equivalences and cofibrations on $H$-orbits for each $H \\leq
G$. We show that a weak equivalence between objects that are fibrant in t
his new model structure is a weak equivalence in the fixed point model str
ucture. This is a joint work with Aslı Güçlükan İlhan.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adalet Çengel (Boğaziçi University)
DTSTART:20190405T113000Z
DTEND:20190405T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/67
DESCRIPTION:Title: Signatures of Lefschetz fibrations\nby Adalet Çengel (Boğ
aziçi University) as part of Yeditepe Mathematics Seminars\n\nLecture hel
d in Seminar Room.\n\nAbstract\nDonaldson has shown that a closed symplect
ic $4$-manifold up to blow-up is equivalent to that of a Lefschetz fibrati
on over the $2$-sphere. The topology of the total space of a Lefschetz fib
ration is completely determined by its monodromy representation which is a
product of positive Dehn twists.\n\nWe give an algorithm to compute signa
ture of a given Lefschetz fibration over $2$-disk by using its monodromy f
actorization. Our main tool will be Wall’s non-additivity formula applie
d to what we call partial fiber sum decomposition of a Lefschetz fibration
over disk. We show that our algorithm works for Lefschetz fibrations with
regular fiber having nonempty boundary. When the regular fibers are close
d\, it is a reformulation of Burak Özbağcı’s algorithm which is descr
ibed in his Ph.D. thesis for the calculation of signatures of Lefschetz fi
brations. This is a joint work with Çağrı Karakurt.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Özgün Ünlü (Bilkent University)
DTSTART:20190412T113000Z
DTEND:20190412T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/68
DESCRIPTION:Title: Free Group Actions on Products of Spheres\nby Özgün Ünl
ü (Bilkent University) as part of Yeditepe Mathematics Seminars\n\nLectur
e held in Seminar Room.\n\nAbstract\nWe will first discuss some known cond
itions on groups that can\nact freely on certain products of spheres. The
n we will review some\nknown conjectures about free group actions on produ
cts of spheres.\nFinally\, we will talk about some recently employed metho
ds for\nconstructing free group actions on products of spheres.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ayşe Borat (Bursa Technical University)
DTSTART:20190426T113000Z
DTEND:20190426T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/69
DESCRIPTION:Title: Directed topological complexity of spheres\nby Ayşe Borat
(Bursa Technical University) as part of Yeditepe Mathematics Seminars\n\nL
ecture held in Seminar Room.\n\nAbstract\nTopological complexity is a homo
topy invariant which measures how far a space away from admitting a motion
planning algorithm [2]. A new variant of topological complexity given thr
ough directed paths is introduced by Goubault\, Sagnier and Farber in [3].
This new concept is useful for classifying directed spaces. \n\nIn this
talk\, I will give a brief introduction to usual topological complexity an
d directed topological complexity\, and I will discuss directed topologica
l complexity of directed $n$-spheres [1]. This is a joint work with Mark G
rant.\n \nBibliography\n\n[1] A. Borat\, M. Grant\, Directed topological c
omplexity of spheres\, submitted. \\href{https://arxiv.org/pdf/1810.00339.
pdf}{arXiv:1810.00339}. \n\n[2] M. Farber\, Topological complexity of moti
on planning\, Discrete Comput. Geom. 29 (2003)\, no. 2\, 211—221. \n\n[3
] E. Goubault\, A. Sagnier\, M. Farber\, Directed topological complexity\,
submitted. \\href{https://arxiv.org/pdf/1812.09382.pdf}{arXiv:1812.09382}
. \n\\end{thebibliography}}\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rıza Seçkin Adalı (University of Oslo)
DTSTART:20190524T113000Z
DTEND:20190524T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/70
DESCRIPTION:Title: Singularities of Restriction Varieties in $OG(k\,n)$\nby R
ıza Seçkin Adalı (University of Oslo) as part of Yeditepe Mathematics S
eminars\n\n\nAbstract\nRestriction varieties in the orthogonal Grassmannia
n are subvarieties of $OG(k\, n)$ defined by rank conditions given by a fl
ag that is not necessarily isotropic with respect to the relevant symmetri
c bilinear form. In particular orthogonal Schubert varieties are examples
of restriction varieties. In this talk\, I will describe a resolution of s
ingularities for restriction varieties which is inspired by the Bott-Samel
son/Zelevinsky resolution and describe their singular locus. I will also d
iscuss the relation between the singular locus and the image of the resolu
tion of singularities.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/70/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Olcay Coşkun (Boğaziçi University)
DTSTART:20191011T113000Z
DTEND:20191011T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/71
DESCRIPTION:Title: Gluing biset functors\nby Olcay Coşkun (Boğaziçi Univers
ity) as part of Yeditepe Mathematics Seminars\n\nLecture held in Seminar R
oom.\n\nAbstract\nWe develop an obstruction theory for the existence and u
niqueness of a solution to the gluing problem for a biset functor. The obs
truction groups for this theory are reduced cohomology groups of a categor
y of sections. Using this obstruction theory\, we calculate the obstructio
n group for the Dade group of a $p$-group when $p$ is odd. This is a joint
work with Ergün Yalçın.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Serap Öztop Kaptanoğlu (İstanbul University)
DTSTART:20191018T113000Z
DTEND:20191018T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/72
DESCRIPTION:Title: A Survey of Orlicz Algebras on Locally Compact Groups\nby S
erap Öztop Kaptanoğlu (İstanbul University) as part of Yeditepe Mathema
tics Seminars\n\nLecture held in Seminar Room.\n\nAbstract\nLet $G$ be a l
ocally compact group\, $\\Phi$ be a Young\nfunction\, and denote by $L^\\P
hi(G)$ the associated Orlicz space.\nThis talk is a survey of results on B
anach algebra and Banach module structures of Orlicz spaces on $G$ that we
have obtained recently in collaboration with our colleagues. We present c
onditions for an Orlicz algebra to be Arens regular. We investigate their
cohomological properties such as amenability. We determine when an Orlicz
algebra is an operator algebra. Our approach can be applied to a vast vari
ety of cases and extend the results in the classical situation. \n\nThis p
resentation is based on joint works with Ebrahim Samei and Varvara Shepels
ka of University of Saskatchewan\, Canada.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/72/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hakkı Turgay Kaptanoğlu (Bilkent University)
DTSTART:20191025T113000Z
DTEND:20191025T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/73
DESCRIPTION:Title: Shift Operators on Hilbert Harmonic Function Spaces\nby Hak
kı Turgay Kaptanoğlu (Bilkent University) as part of Yeditepe Mathematic
s Seminars\n\nLecture held in Seminar Room.\n\nAbstract\nIn an attempt to
identify the harmonic Drury-Arveson space\, we introduce and investigate
large families of reproducing kernel Hilbert spaces of harmonic functions
the unit ball of $\\mathbb R^n$. Using zonal harmonics\, we define and dev
elop basic properties of shift operators and their adjoints in the harmoni
c setting. We prove a dilation result for the shift operators on harmonic
spaces that are row contractions. As a consequence\, we show that the norm
of one of our spaces Ğ is maximal among those spaces on which the shift
operator is a row contraction. We also show the maximality of the operator
norm of the shift on Ğ among contractive Hilbert norms on harmonic polyn
omials. We then describe the progress towards a von Neumann inequality for
harmonic polynomials and a tuple of commuting operators on harmonic space
s that are row contractions and belong to a certain class.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:İpek Tuvay (Mimar Sinan Fine Arts University)
DTSTART:20191108T113000Z
DTEND:20191108T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/74
DESCRIPTION:Title: An application of Baer-Suzuki Theorem to modular representation
theory\nby İpek Tuvay (Mimar Sinan Fine Arts University) as part of
Yeditepe Mathematics Seminars\n\nLecture held in Seminar Room.\n\nAbstract
\nThe Baer-Suzuki Theorem states that if $p$ is a prime\, $x$ is a $p$-ele
ment in a finite group $G$ and $$ is a $p$-group for every elemen
t $g$ of $G$\, then the conjugacy class of $x$ in $G$ lies in a normal $p$
-subgroup of $G$. In this talk\, we present a very nice application of thi
s theorem and using this we show that for a finite group $G$ with a semidi
hedral subgroup $P$\, the Scott module $Sc(G\,P)$ is Brauer indecomposable
. This is a joint work with Shigeo Koshitani.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/74/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yasemin Kara (Boğaziçi University)
DTSTART:20191129T113000Z
DTEND:20191129T123000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/75
DESCRIPTION:Title: Asymptotic Generalized Fermat’s Last Theorem over Number Fiel
ds\nby Yasemin Kara (Boğaziçi University) as part of Yeditepe Mathem
atics Seminars\n\nLecture held in Seminar Room.\n\nAbstract\nRecent work o
f Freitas and Siksek showed that an asymptotic version of Fermat’s Last
Theorem (FLT) holds for many totally real fields. This\nresult was extende
d by Deconinck to the generalized Fermat equation of\nthe form $Ax^p + By^
p + Cz^p = 0$\, where $A\, B\, C$ are odd integers belonging\nto a totally
real field. Later Şengün and Siksek showed that the asymptotic FLT hold
s over number fields assuming two standard modularity\nconjectures.\n\nIn
this work\, combining their techniques we show that the generalized\nFerma
t’s Last Theorem (GFLT) holds over number fields asymptotically\nassumin
g the standard conjectures. We also give three results which show\nthe exi
stence of families of number fields on which asymptotic versions of\nFLT o
r GFLT hold. In particular\, we prove that the asymptotic GFLT\nholds for
a set of imaginary quadratic number fields of density $5/6$.\n\nThis is a
joint work with Ekin Özman.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ekin Özman (Boğaziçi University)
DTSTART:20240419T100000Z
DTEND:20240419T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/76
DESCRIPTION:Title: Modular Curves\, Rational Points and Diophantine Equations\
nby Ekin Özman (Boğaziçi University) as part of Yeditepe Mathematics Se
minars\n\n\nAbstract\nExploring solutions to Diophantine equations over a
number field stands as a key challenge in number theory. Using the modular
techniques employed by Wiles in proving Fermat’s last theorem and its e
xtensions\, we can extend our ability to solve various Diophantine equatio
ns. Additionally\, understanding points on the classical modular curve con
tributes significantly to this methodology. In this presentation\, I will
address specific questions and share results that have emerged from this a
rea of study.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mahmut Elbistan (İstanbul Bilgi University)
DTSTART:20240503T100000Z
DTEND:20240503T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/77
DESCRIPTION:Title: Various disguises of the Pais-Uhlenbeck oscillator\nby Mahm
ut Elbistan (İstanbul Bilgi University) as part of Yeditepe Mathematics S
eminars\n\n\nAbstract\nPais-Uhlenbeck oscillator is one of the best known
higher derivative models. In this talk\, I will discuss realizations of th
is mechanical model in physical setups with second order equations of moti
on. I will explicitly show that dynamics in some certain gravitational wav
es in 4 dimensions and Penning trap in 3 dimensions are governed by 1-dime
nsional Pais-Uhlenbeck oscillator.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kadri İlker Berktav (Bilkent University)
DTSTART:20240329T100000Z
DTEND:20240329T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/78
DESCRIPTION:Title: Symplectic and contact structures on derived stacks\nby Kad
ri İlker Berktav (Bilkent University) as part of Yeditepe Mathematics Sem
inars\n\n\nAbstract\nIn this talk\, we outline our program for the develop
ment of shifted contact structures in the context of derived algebraic geo
metry. We start by recalling some key notions and results from derived alg
ebraic/symplectic geometry. Next\, we discuss shifted contact structures o
n derived Artin stacks and report our results on their local theory and sa
mple constructions.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emine Yıldırım Kaygun (University of Leeds)
DTSTART:20240524T100000Z
DTEND:20240524T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/79
DESCRIPTION:Title: From Triangulations to Friezes and Cluster Algebras\nby Emi
ne Yıldırım Kaygun (University of Leeds) as part of Yeditepe Mathematic
s Seminars\n\n\nAbstract\nIn this talk\, we first talk about some combinat
orics on the triangulated surfaces and then show interesting connections t
o up-to-date research topics like Friezes and Cluster algebras. This prese
ntation will include some collaborative work with K. Baur\, L. Bittman\, E
. Gunawan\, and G. Todorov. If time permits\, we will also explore more on
computational aspects which is another collaborative work with E. Kantarc
ı Oğuz.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dilara Karslıoğlu (Yeditepe University)
DTSTART:20240517T100000Z
DTEND:20240517T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/80
DESCRIPTION:Title: On the Blow-up Solutions to a Fourth-Order Pseudo-Parabolic Equ
ation with Gradient Non-Linearity\nby Dilara Karslıoğlu (Yeditepe Un
iversity) as part of Yeditepe Mathematics Seminars\n\nLecture held in Math
ematics&Physics Seminar Room.\n\nAbstract\nIn this study\, the initial and
periodic boundary value problem was solved for the following fourth-orde
r pseudo-parabolic equation with gradient non-linearity and pseudo term \n
$$ u_t-a\\Delta u_t-\\Delta u+\\Delta^2u=-\\nabla\\cdot(|\\nabla u|^{p-2}
\\nabla u)$$\nwhere $a\\ge 0$. Local existence-uniqueness result for mild
solutions was found for any initial data in $L^2(\\Omega)$. In addition\,
the existence of blow-up solutions was proved and a lower bound for the b
low-up time was obtained.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Deniz Karlı (Işık University)
DTSTART:20241218T103000Z
DTEND:20241218T113000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/82
DESCRIPTION:Title: Stochastic Analysis For Singular Integral Operators and Fracti
onal Derivatives\nby Deniz Karlı (Işık University) as part of Yedit
epe Mathematics Seminars\n\nLecture held in Yeditepe Math Seminar Room.\n\
nAbstract\nOn the cross-section of Probability Theory and Analysis\, singu
lar integral operators and related boundedness problems of Analysis are st
udied by means of stochastic processes. One of the main problems is to det
ermine a general class of multipliers and so the bounded operators on func
tion spaces. In this talk\, we use a discontinuous process\, namely a symm
etric stable process\, to show boundedness results of extended versions of
classical singular integral operators which arises from classical multipl
iers. In the first part of our talk\, we will discuss how one can build th
e connection between integral operators in Classical Analysis and Stochast
ic Analysis. We will introduce versions of intermediate operators appearin
g in the Littlewood-Paley Theory and show recent boundedness results. The
second part of our talk will present the relation between these new operat
ors and fractional derivative in its integral form and we discuss multipli
ers defined in terms of fractional derivatives. We show an extended class
of multipliers obtained through a new version of Mikhlin Multiplier Theore
m and explain why classical multipliers form a sublass of this new extende
d class of multipliers.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Devrim Bilgili (University of Florida)
DTSTART:20241204T130000Z
DTEND:20241204T140000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/83
DESCRIPTION:Title: Size and shape analysis of silica (SiO2) and gold (Au) nanopart
icles\nby Devrim Bilgili (University of Florida) as part of Yeditepe M
athematics Seminars\n\n\nAbstract\nIn nanotechnology\, the size and shape
control of nanoparticles is crucial as their properties are highly depende
nt on their morphology. This obliges researchers to work on obtaining unif
orm size and shape distribution in synthesized particles so that their ele
ctrical\, optical\, and magnetic properties remain uniform within the same
batch. This brings the problem of how to quantify the shape and size of n
anoparticles in the most accurate way. The most common way to determine si
ze distribution is using UV-vis spectrometry\; however\, this method disre
gards the existence of agglomerated particles and may sometimes give an in
correct measurement. Therefore a technique that can obtain this data direc
tly from the transmission electron microscopy (TEM) images of particles wo
uld be more reliable as it would capture data for every single particle in
the batch. In a classical statistical sense\, our interest is the shape a
nd size distribution of nanoparticles. In this paper\, we quantify the siz
e and shape of nanoparticles using the statistical techniques applied on T
EM images of particles: Functional Data and Shape Analysis. By using this
shape theory we obtain the geodesic distances not only between the particl
es but also among the frames. We further cluster the nanoparticles in term
s of their similarities. We want to emphasize the importance of the deform
ation and how it is done from one nanoparticle onto another.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/83/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tekin Dereli (Koç University)
DTSTART:20241127T100000Z
DTEND:20241127T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/86
DESCRIPTION:Title: Electromagnetic Hertz potentials and the Cabibbo-Ferrari theory
of magnetic monopoles\nby Tekin Dereli (Koç University) as part of Y
editepe Mathematics Seminars\n\nLecture held in Yeditepe Math Seminar Room
.\n\nAbstract\nAfter a brief review of differential geometric gauge aspect
s of Maxwell equations I am going to introduce Hertz potentials for electr
o-magnetic fields. This formalism allows for establishing a manifest duali
ty invariance of the Maxwell-Lorentz electrodynamics. As an application I
will discuss the Cabibbo-Ferrari theory of magnetic monopoles.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Halit Şevki Aslan (University of São Paulo)
DTSTART:20241030T100000Z
DTEND:20241030T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/87
DESCRIPTION:Title: $L^p-L^q$ estimates for solutions to the plate equation with ma
ss term\nby Halit Şevki Aslan (University of São Paulo) as part of Y
editepe Mathematics Seminars\n\n\nAbstract\nIn this talk\, we are going to
study the following Cauchy problem for the plate equation with mass term:
\n$$u_{tt} + \\Delta^2u + u = 0\\ \\text{if} \\ (t\,x)\\in (0\,\\infty)\\
times \\mathbb{R}^n$$\n $$u(0\,x)=u_0(x)\\ \\ u_t(0\,x)=u_1(x)\\ \\ \\text
{if} \\ x\\in \\mathbb{R}^n.$$\nOur goal is to derive $L^p-L^q$ estimates
for the solutions to problem \\eqref{eq_1} in the full range $1 \\leq p \
\leq q \\leq \\infty$. After that\, we study the associated semilinear mod
el with power non-linearity $|u|^{\\alpha}$ with $\\alpha>1$\, where we ap
ply the derived $L^p-L^q$ estimates in the analysis of local (in time) exi
stence of solution and for the global (in time) small data solutions.\n\nT
he results of this talk are based on collaboration with} \n\n Alexandre A.
Junior (University of S\\~ao Paulo\, Ribeir\\~ao Preto\, Brazil)\,\n\nMar
celo R. Ebert (University of S\\~ao Paulo\, Ribeir\\~ao Preto\, Brazil)\,\
n\nAntonio Lagioia (University of Bari\, Italy).\n\nReferences\n\n[1] M. D
'Abbicco\, M.R. Ebert\, $L^p-L^q$ estimates for a parameter-dependent mult
iplier with oscillatory and diffusive components. J. Math. Anal. Appl. {50
4} (2021).\n\n\n[2] M. Ikeda\, T. Inui\, A remark on non-existence results
for the semi-linear damped Klein-Gordon equations. RIMS Kôkyûroku Bessa
tsu B56\, (2016)\, 11--30.\n\n[3] B. Marshall\, W. Strauss\, S. Wainger\,
$L^p-L^q$ estimates for the Klein-Gordon equation. J. Math. Pures Appl. 59
. (1980) 417--440.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/87/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sultan Sütlü (Acıbadem University)
DTSTART:20241225T100000Z
DTEND:20241225T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/88
DESCRIPTION:Title: A Stability Study by Routh-Hurwitz Criterion and Gershgorin Cir
cles for Infectious Diseases\nby Sultan Sütlü (Acıbadem University)
as part of Yeditepe Mathematics Seminars\n\nLecture held in Yeditepe Math
Seminar Room.\n\nAbstract\nThe mathematical theory of infectious diseases
and epidemics has always been interesting for many branches of science. I
n this talk\, we present the stabilization problem on a model for Covid-19
by using the Routh-Hurwitz criterion and Gershgorin circles. Using Routh-
Hurwitz criterion\, we prove the necessity of unstability and stability co
nditions for the model that we extend from an existing one. We give the ne
cessary conditions for stability on this model by using the Gershgorin Cir
cle Theorem and give examples.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/88/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Başak Küçük (University of Göttingen)
DTSTART:20250418T100000Z
DTEND:20250418T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/89
DESCRIPTION:Title: Homotopical Obstruction to Fixed Points of Equivariant Maps
\nby Başak Küçük (University of Göttingen) as part of Yeditepe Mathem
atics Seminars\n\n\nAbstract\nThe Lefschetz number provides an obstruction
theory for the classical fixed point problem\, which asks whether a given
map can be homotoped to one without fixed points. According to the Lefsch
etz fixed point theorem\, if a self-map on a compact triangulable space ha
s no fixed points\, then its Lefschetz number must be zero. However\, the
converse does not necessarily hold. A more refined invariant\, the Nielsen
number\, provides a converse under a certain dimension condition.\nIn thi
s talk\, we explore a more general version of the fixed point problem in t
he equivariant setting. Klein and Williams developed an obstruction theory
for equivariant fixed points [2\, Theorem H]. An alternative approach\, b
ased on a collection of Nielsen numbers\, was proposed by Fadell and Wong
[1]. It was stated as a conjecture in [2] whether these Nielsen numbers ca
n be computed from the Klein-Williams invariant. We will begin by defining
the Nielsen number and then discuss the construction of the Klein-William
s invariant. The talk will conclude with a focus on the conjecture in [2]
and present results addressing this question.\n\nReferences\n\n[1] Edward
Fadell and Peter Wong. On deforming G-maps to be fixed point free. Pacific
Journal of Mathematics\, 132(2):277 – 281\, 1988.\n\n[2] John R. Klein
and Bruce Williams. Homotopical intersection theory\, II: Equivariance. Ma
th. Z.\, 264(4):849–880.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/89/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Orendain (Case Western Reserve University)
DTSTART:20250516T150000Z
DTEND:20250516T160000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/92
DESCRIPTION:Title: Compositional Quantum Field Theory\nby Juan Orendain (Case
Western Reserve University) as part of Yeditepe Mathematics Seminars\n\n\n
Abstract\nCompositional Quantum Field Theory (CQFT) is an axiomatic framew
ork for reasoning about Quantum Field Theory\, based on the principles of
locality and compositionality. The first ingredient of CQFT is a spacetime
gluing syntax based on gluing maps and gluing diagrams. I will present th
is in detail. Once this is set up\, I will introduce CQFT axiomatically\,
and I will show how to recast these axioms as a type of functorial semanti
cs translating our spacetime syntax into Hilbert spaces\, using algebras o
ver *-operads and constrained maps between them. Finally\, we will investi
gate how in CQFT in dimension 2\, e.g. in 2 dimensional Quantum Yang-Mills
theory\, our functorial semantics viewpoint allows for certain structures
to emerge from first principles. An example of this is the structure of c
yclic\, involutive A_oo-algebra on the state space of the interval.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/92/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sema Salur (University of Rochester)
DTSTART:20250509T100000Z
DTEND:20250509T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/93
DESCRIPTION:Title: Manifolds with Special Holonomy\nby Sema Salur (University
of Rochester) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nMani
folds with special holonomy\, such as Calabi–Yau and G₂\nmanifolds\, a
re Riemannian manifolds whose holonomy groups are\ncontained in SU(n) (for
n = 2m) and the exceptional Lie group G₂ (for\nn = 7)\, respectively. T
hese spaces arise naturally as Ricci-flat\nexamples in differential geomet
ry and play a central role in\ntheoretical physics\, particularly in M-the
ory compactifications.\nM-theory\, often described as a candidate for a "t
heory of\neverything''\, aims to unify the fundamental forces of nature:\n
electromagnetism\, gravity\, and the strong and weak nuclear forces.\n\nCa
librated submanifolds within Calabi–Yau and G₂ manifolds are volume\nm
inimizing in their homology classes\, and their moduli spaces have\ndeep a
pplications in geometry\, topology\, and physics. In this talk\, we\nwill
begin with a brief introduction to Calabi–Yau and G₂ manifolds\,\nand
then report on recent research exploring the rich interplay\nbetween sympl
ectic\, contact\, and calibrated structures in manifolds\nwith special hol
onomy.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/93/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Justyna Ogorzały (Military University of Technology of Warsaw)
DTSTART:20250704T100000Z
DTEND:20250704T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/94
DESCRIPTION:Title: Variational-Hemivariational Inequalities with Applications to C
ontact Mechanics\nby Justyna Ogorzały (Military University of Technol
ogy of Warsaw) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nWe
will present the existence and uniqueness results for a class of abstract
nonlinear variational-hemivariational inequalities. Next\, we will present
applications of the abstract results into the analysis of concrete contac
t problems.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/94/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Orsan Kılıçer (Texas A&M University)
DTSTART:20250815T100000Z
DTEND:20250815T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/95
DESCRIPTION:Title: Higher Order FEM for Surface Stokes Problems\nby Orsan Kıl
ıçer (Texas A&M University) as part of Yeditepe Mathematics Seminars\n\n
\nAbstract\nThis research focuses on developing a higher-order finite elem
ent method for solving the Surface Stokes Problem. Finite element methods
face challenges due to the possible ill-posedness caused by Killing fields
\, and an $H^1$-conforming method cannot be constructed for merely $C^0$ d
iscrete surfaces.\n\nTo address these difficulties\, this work introduces
a mass term into both the weak and strong formulations and employs an H(di
v)-conforming $BDM_k - P_{k-1}$ pair for velocity and pressure while using
Lagrange interpolation for higher-order surface approximations.\n\nThe st
udy analyzes discrete Korn-type inequalities\, discrete inf-sup conditions
\, norm equivalencies on discrete and continuous surfaces\, and both geome
tric and Galerkin errors associated with the proposed method.\n\nTheoretic
al error estimates demonstrate sharp energy error convergence for velocity
and $L^2$ error convergence for pressure\, which align well with numerica
l results. However\, in theory\, a suboptimal $L^2$ velocity error estimat
e is observed due to geometric error limitations.\n\nOverall\, this resear
ch provides a stable finite element framework for solving the Surface Stok
es Problem. The findings contribute to the numerical analysis of surface p
artial differential equations and offer a foundation for further improveme
nts in geometric error estimation.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/95/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Richard Gonzales (IHES - PUCP)
DTSTART:20250919T100000Z
DTEND:20250919T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/96
DESCRIPTION:Title: Equivariant cohomology of group embeddings\nby Richard Gonz
ales (IHES - PUCP) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\
nIn this talk I will describe how the symmetries of a variety (encoded via
a group action) can be used to understand the geometry and topology not o
nly of the variety itself\, but also of higher structures defined on it\,
like vector bundles or sheaves. The study of those structures that are lef
t invariant under the group action leads naturally to the notion of equiva
riant cycles and related topological invariants (e.g. Chow groups). Moreov
er\, in many cases of interest (e.g. group embeddings or compactifications
of reductive groups) these topological invariants can be read off from a
suitable combinatorial object\, like a graph or a fan\, leading to nice co
mbinatorial descriptions of the corresponding cohomology. In this talk I w
ill describe how the symmetries of a variety (encoded via a group action)
can be used to understand the geometry and topology not only of the variet
y itself\, but also of higher structures defined on it\, like vector bundl
es or sheaves. The study of those structures that are left invariant under
the group action leads naturally to the notion of equivariant cycles and
related topological invariants (e.g. Chow groups). Moreover\, in many case
s of interest (e.g. group embeddings or compactifications of reductive gro
ups) these topological invariants can be read off from a suitable combinat
orial object\, like a graph or a fan\, leading to nice combinatorial descr
iptions of the corresponding cohomology.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/96/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yıldıray Ozan (METU)
DTSTART:20251212T100000Z
DTEND:20251212T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/97
DESCRIPTION:Title: Orientations of Vector Spaces and Manifolds\nby Yıldıray
Ozan (METU) as part of Yeditepe Mathematics Seminars\n\nLecture held in Ye
ditepe Math Seminar Room.\n\nAbstract\nIn this talk\, we will first define
an orientation of a real \nvector space. After introducing the natural or
ientation of complex \nvector spaces\, we will discuss the orientations of
manifolds. In this \ncontext\, we will discuss the geometric consequences
of the natural \norientations of complex manifolds. Finally\, we will dis
cuss the \ninability of the real projective plane\, the simplest example o
f an \nunorientable manifold\, to be embedded in three-dimensional Euclide
an \nspace. If time permits\, we will discuss a geometric consequence of \
nthis result.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Massimo Lanza de Cristoforis (Università degli Studi di Padova)
DTSTART:20251219T093000Z
DTEND:20251219T103000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/98
DESCRIPTION:Title: Representation theorems for nonvariational solutions of the He
lmholtz equation\nby Massimo Lanza de Cristoforis (Università degli S
tudi di Padova) as part of Yeditepe Mathematics Seminars\n\n\nAbstract\nWe
consider a bounded open subset $\\Omega$ of ${\\mathbb{R}}^n$ of class $C
^{1\,\\alpha}$ for some\n$\\alpha\\in]0\,1[$ and we plan to present integr
al representation theorems for $\\alpha$-H\\"{o}lder continuous solutions
of the Helmholtz equation in $\\Omega$ and in the exterior of $\\Omega
$\nthat may have an infinite Dirichlet integral around the boundary of $\\
Omega$. Thus for solutions that do not belong to the classical variation
al setting.\n\nSeminar will start at 12:30.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/98/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gönenç Onay (Galatasaray University)
DTSTART:20251107T100000Z
DTEND:20251107T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/99
DESCRIPTION:Title: Laurent Series in Positive Characteristic: Axiomatization Probl
ems\nby Gönenç Onay (Galatasaray University) as part of Yeditepe Mat
hematics Seminars\n\n\nAbstract\nLaurent Series in Positive Characteristic
: Axiomatization Problems Valued fields combine algebraic and analytic str
uctures through valuations. This talk focuses on axiomatization and decida
bility problems for Laurent series fields in positive characteristic. Afte
r surveying classical results\, I will present my contributions on valued
fields equipped with endomorphisms—a natural framework in characteristic
p where the Frobenius map provides a canonical self-endomorphism—and di
scuss axiomatization challenges for the field of Laurent series over the p
rime field of characteristic p (resp. over algebraically closed fields of
characteristic p). The presentation will remain accessible to non-speciali
sts.\n\nYeditepe University Math-Physics Seminar Room\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/99/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roghayeh Hafezieh (Gebze Technical University)
DTSTART:20251205T100000Z
DTEND:20251205T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/100
DESCRIPTION:Title: The solvability criterion for finite groups considering vanish
ing classes\nby Roghayeh Hafezieh (Gebze Technical University) as part
of Yeditepe Mathematics Seminars\n\nLecture held in Yeditepe Math Seminar
Room.\n\nAbstract\nFor a finite group $G$\, an element is called a vanish
ing element of $G$ if it is a zero of an irreducible character of $G$\; ot
herwise\, it is called a non-vanishing element. Moreover\, the conjugacy c
lass of an element is termed as a vanishing class if that element is a van
ishing element. In this talk\, we present a solvability criterion with res
pect to the set of vanishing class sizes.\n\nThe talk will be in class.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/100/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rüya Üster (İstanbul University)
DTSTART:20251128T100000Z
DTEND:20251128T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/101
DESCRIPTION:Title: Orlicz modülasyon uzayları ve pseudo-diferansiyel operatörl
er\nby Rüya Üster (İstanbul University) as part of Yeditepe Mathema
tics Seminars\n\n\nAbstract\nBu konuşmada pseudo-diferansiyel operatörle
rin süreklilik özelliklerini Orlicz modülasyon uzaylarında inceleyece
ğiz. Orlicz modülasyon uzayları klasik Lebesgue modülasyon uzayların
ı da içerdi˘ginden elde ettiğimiz sonuçlar literatürde bilinen sonu
çları da kapsayacaktır.\n\nBu çalışma J.Toft\, N. Rana ve A. Gumber
ile ortak araştırmanın ürünüdür\n\nPlease note that the talk will b
e in Turkish.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/101/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fatih Şirin (Haliç University)
DTSTART:20251114T100000Z
DTEND:20251114T110000Z
DTSTAMP:20260315T024443Z
UID:7tepemathseminars/102
DESCRIPTION:Title: Rubio de Francia Extrapolation: From Scalar to Matrix Weighted
Spaces\nby Fatih Şirin (Haliç University) as part of Yeditepe Mathe
matics Seminars\n\n\nAbstract\nThe theory of weighted inequalities is a fo
undational component of modern harmonic analysis. The Rubio de Francia ext
rapolation theorem provides a powerful principle: the boundedness of an op
erator on a single weighted Lebesgue space for all Muckenhoupt weights imp
lies corresponding bounds on for every . This theorem offers a unified fra
mework for many classical estimates.\n\nIn this talk\, we will first revie
w the classical extrapolation theory in the scalar-\nweighted setting\, hi
ghlighting the structure of weights and the role of the\nHardy–Littlewoo
d maximal operator. We then introduce the extension of extrapolation metho
ds to matrix weights\, where new geometric and analytic challenges arise.
The matrix-weighted framework allows us to study vector-valued operators a
nd yields broad applications to singular integral theory.\n
LOCATION:https://researchseminars.org/talk/7tepemathseminars/102/
END:VEVENT
END:VCALENDAR