BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Matthew Pressland (University of Leeds)
DTSTART;VALUE=DATE-TIME:20200521T130000Z
DTEND;VALUE=DATE-TIME:20200521T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/1
DESCRIPTION:Title: Calabi–Yau properties of Postnikov diagrams\nby Matthew Pressland
(University of Leeds) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Pauksztello (Lancaster University)
DTSTART;VALUE=DATE-TIME:20200528T130000Z
DTEND;VALUE=DATE-TIME:20200528T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/2
DESCRIPTION:Title: Simple-mindedness: negativity and positivity\nby David Pauksztello
(Lancaster University) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Labardini-Fragoso (UNAM)
DTSTART;VALUE=DATE-TIME:20200604T130000Z
DTEND;VALUE=DATE-TIME:20200604T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/3
DESCRIPTION:Title: Schemes of modules over gentle algebras and laminations of surfaces
\nby Daniel Labardini-Fragoso (UNAM) as part of FD Seminar\n\nAbstract: TB
A\n
LOCATION:https://researchseminars.org/talk/fd-seminar/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Haruhisa Enomoto (Nagoya University)
DTSTART;VALUE=DATE-TIME:20200618T130000Z
DTEND;VALUE=DATE-TIME:20200618T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/4
DESCRIPTION:Title: Simple objects in torsion-free classes over preprojective algebras of D
ynkin type\nby Haruhisa Enomoto (Nagoya University) as part of FD Semi
nar\n\n\nAbstract\nIn this talk\, I propose to study exact-categorical str
uctures of torsion(-free) classes of module categories. For functorially f
inite torsion-free class\, indecomposable projective and injective objects
are easily described by \\tau^-τ \n−\n -tilting modules\, and in parti
cular\, the numbers of them coincide. However\, there can be more simple o
bjects in torsion-free class\, which I propose to study. I explain that th
e number of simple objects controls the validity of the Jordan–Hölder t
ype theorem in a torsion-free class.\n\nThen I’ll talk about simple obje
cts in a torsion-free class over the preprojective algebra (and path algeb
ra) of Dynkin type\, which is also important in Lie theory due to Geiss–
Leclerc–Schröer’s categorification of the cluster structure. By Mizun
o’s result\, we can associate an element ww of the Weyl group to each to
rsion-free class \\mathcal{F}F. By (extended) Gabriel’s theorem\, \\math
cal{F}F roughly corresponds to the inversion set of ww\, the set of positi
ve roots which are sent to negative by w^{-1}w \n−1\n . Then I show that
simple objects in \\mathcal{F}F are in bijection with Bruhat inversions o
f ww\, which are related to the Bruhat order of the Weyl group.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Louis-Philippe Thibault (NTNU)
DTSTART;VALUE=DATE-TIME:20200611T130000Z
DTEND;VALUE=DATE-TIME:20200611T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/5
DESCRIPTION:by Louis-Philippe Thibault (NTNU) as part of FD Seminar\n\nAbs
tract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Schiffler (University of Connecticut)
DTSTART;VALUE=DATE-TIME:20200625T130000Z
DTEND;VALUE=DATE-TIME:20200625T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/6
DESCRIPTION:Title: A geometric model for the syzygies over certain 2-Calabi--Yau tilted al
gebras\nby Ralf Schiffler (University of Connecticut) as part of FD Se
minar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claire Amiot (Université Joseph Fourier)
DTSTART;VALUE=DATE-TIME:20200702T130000Z
DTEND;VALUE=DATE-TIME:20200702T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/7
DESCRIPTION:Title: Derived equivalences for skew-gentle algebras\nby Claire Amiot (Uni
versité Joseph Fourier) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Karin Baur (University of Leeds)
DTSTART;VALUE=DATE-TIME:20200716T130000Z
DTEND;VALUE=DATE-TIME:20200716T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/8
DESCRIPTION:Title: Postnikov diagrams and orbifolds\nby Karin Baur (University of Leed
s) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Špela Špenko (Université libre de Bruxelles)
DTSTART;VALUE=DATE-TIME:20200730T130000Z
DTEND;VALUE=DATE-TIME:20200730T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/9
DESCRIPTION:Title: GKZ systems and perverse schobers\nby Špela Špenko (Université l
ibre de Bruxelles) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Solotar (Universidad de Buenos Aires)
DTSTART;VALUE=DATE-TIME:20200709T130000Z
DTEND;VALUE=DATE-TIME:20200709T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/10
DESCRIPTION:Title: Bounded extension algebras and Han's conjecture\nby Andrea Solotar
(Universidad de Buenos Aires) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cris Negron (University of North Carolina)
DTSTART;VALUE=DATE-TIME:20200723T130000Z
DTEND;VALUE=DATE-TIME:20200723T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/11
DESCRIPTION:Title: Finite generation of cohomology for Drinfeld doubles of finite group s
chemes\nby Cris Negron (University of North Carolina) as part of FD Se
minar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bernhard Keller (Université de Paris)
DTSTART;VALUE=DATE-TIME:20200903T130000Z
DTEND;VALUE=DATE-TIME:20200903T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/12
DESCRIPTION:Title: Relative Calabi-Yau completions and higher preprojective algebras\
nby Bernhard Keller (Université de Paris) as part of FD Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shijie Zhu (The University of Iowa)
DTSTART;VALUE=DATE-TIME:20200910T140000Z
DTEND;VALUE=DATE-TIME:20200910T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/13
DESCRIPTION:Title: Hopf algebras of discrete representation type\nby Shijie Zhu (The
University of Iowa) as part of FD Seminar\n\n\nAbstract\nHopf algebra is a
n important topic in geometric representation theory. A basic algebra is o
f finite representation type if there are only finitely many non-isomorphi
c indecomposable representations. Basic Hopf algebras of finite representa
tion type have been classified by Liu and Li in 2004. As algebras\, they a
re just copies of Nakayama algebras. A pointed coalgebra is of discrete re
presentation type\, if there are only finitely many non-isomorphic indecom
posable representations for each dimension vector. In this talk\, I am goi
ng to give a classification of pointed Hopf algebras of discrete represent
ation type. The main tool we are using is called “covering maps” of (f
inite dimensional) coalgebras which comes from separable extensions of the
dual algebras. This is a joint work with Miodrag Iovanov\, Emre Sen\, and
Alexander Sistko.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jenny August (Max Plank Institut für Mathematik (MPIM))
DTSTART;VALUE=DATE-TIME:20200917T130000Z
DTEND;VALUE=DATE-TIME:20200917T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/14
DESCRIPTION:Title: Grassmanian categories of infinite rank\nby Jenny August (Max Plan
k Institut für Mathematik (MPIM)) as part of FD Seminar\n\n\nAbstract\nIn
this talk\, I’ll describe our work towards providing an infinite rank v
ersion of the Grassmanian cluster categories introduced by Jensen\, King a
nd Su. We develop a new combinatorial tool for determining when two k-subs
ets of the integers are “non-crossing”\, or equivalently when two Plü
cker coordinates of a Grassmanian cluster algebra of infinite rank are “
compatible”. We use this tool to show that there is a structure preservi
ng bijection between these Plücker coordinates and the generically free m
odules of rank 1 in our Grassmanian category of infinite rank\, mirroring
a result of Jensen\, King and Su in the finite case. This is joint work wi
th Man-Wai Cheung\, Eleonore Faber\, Sira Gratz and Sibylle Schroll.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xiao-Wu Chen (University of Science and Technology of China (USTC)
)
DTSTART;VALUE=DATE-TIME:20200924T130000Z
DTEND;VALUE=DATE-TIME:20200924T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/15
DESCRIPTION:Title: Leavitt path algebras\, B-infty-algebras and Keller’s conjecture for
singular Hochschild cohomology\nby Xiao-Wu Chen (University of Scienc
e and Technology of China (USTC)) as part of FD Seminar\n\n\nAbstract\nI w
ill first recall the relation between Leavitt path algebras and the singul
arity categories of radical-square-zero algebras. Using Leavitt path algeb
ras\, we confirm Keller’s conjecrure for any radical-square-zero algebra
: there is an isomorphism in the homotopy category of $B_\\infty$-algebras
between the Hochschild cochain complex of the dg singularity category and
the singular Hochschild cochain complex of the algebra. Moreover\, we pro
ve that Keller’s conjecture is invariant under one-point (co)extensions
and singular equivalences with levels. This is joint with Huanhuan Li and
Zhengfang Wang.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stephen Zito (University of Connecticut)
DTSTART;VALUE=DATE-TIME:20201001T130000Z
DTEND;VALUE=DATE-TIME:20201001T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/16
DESCRIPTION:Title: tau-Tilting Finite Algebras With Non-Empty Left Or Right Parts Are Rep
resentation-Finite\nby Stephen Zito (University of Connecticut) as par
t of FD Seminar\n\n\nAbstract\nτ-tilting theory was introduced by Adachi\
, Iyama and Reiten as a far-reaching generalization of classical tilting t
heory for finite dimensional associative algebras. One of the main classes
of objects in the theory is that of τ\\tauτ-rigid modules: a module MMM
over an algebra Λ\\LambdaΛ is τ\\tauτ-rigid if HomΛ(M\,τM)=0\\op
eratorname{Hom}_{\\Lambda}(M\,\\tau M)=0HomΛ(M\,τM)=0\, where τM\\ta
u MτM denotes the Auslander-Reiten translation of MMM\; such a module MMM
is called τ\\tauτ-tilting if the number ∣M∣|M|∣M∣ of non-isomor
phic indecomposable summands of MMM equals the number of isomorphism class
es of simple Λ\\LambdaΛ-modules. Recently\, a new class of algebras was
introduced by Demonet\, Iyama\, Jasso called τ\\tauτ-tilting finite alge
bras. They are defined as finite dimensional algebras with only a finite n
umber of isomorphism classes of basic τ\\tauτ-tilting modules.\n\nAn obv
ious sufficient condition to be τ\\tauτ-tilting finite is to be represen
tation-finite. In general\, this condition is not necessary. The aim of th
is talk is to show for algebras Λ\\LambdaΛ such that LΛL_\\LambdaLΛ
or RΛ≠∅R_\\Lambda\\neq\\emptysetRΛ=∅ \, representation-f
initeness and τ\\tauτ-tilting finiteness are equivalent conditions.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lidia Angeleri Hügel (Università degli Studi di Verona)
DTSTART;VALUE=DATE-TIME:20201217T140000Z
DTEND;VALUE=DATE-TIME:20201217T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/17
DESCRIPTION:by Lidia Angeleri Hügel (Università degli Studi di Verona) a
s part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fernando Muro (TBC) (Universidad de Sevilla)
DTSTART;VALUE=DATE-TIME:20201210T140000Z
DTEND;VALUE=DATE-TIME:20201210T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/18
DESCRIPTION:by Fernando Muro (TBC) (Universidad de Sevilla) as part of FD
Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vanessa Miemietz (University of East Anglia)
DTSTART;VALUE=DATE-TIME:20201022T130000Z
DTEND;VALUE=DATE-TIME:20201022T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/20
DESCRIPTION:Title: Categorification of representation theory with an application to Soerg
el bimodules\nby Vanessa Miemietz (University of East Anglia) as part
of FD Seminar\n\n\nAbstract\nWe explain how to categorify various basic re
sults from the representation theory of finite-dimensional algebras\, whic
h are useful for classifying simple modules\, to the 2-representation theo
ry of fiat 2-categories. We then apply these in order to obtain a classifi
cation of simple 2-representations of the 2-category of Soergel bimodules.
\n
LOCATION:https://researchseminars.org/talk/fd-seminar/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dmitri Orlov (Steklov Mathematical Institute of Russian Academy of
Sciences)
DTSTART;VALUE=DATE-TIME:20201029T140000Z
DTEND;VALUE=DATE-TIME:20201029T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/21
DESCRIPTION:Title: Finite-dimensional DG algebras and their properties\nby Dmitri Orl
ov (Steklov Mathematical Institute of Russian Academy of Sciences) as part
of FD Seminar\n\n\nAbstract\nThe talk will focus on finite-dimensional DG
algebras and categories of perfect complexes over such DG algebras. These
categories can be considered as proper derived noncommutative schemes. We
are going to discuss basic properties of these noncommutative schemes and
to establish a connection between such categories and DG categories with
(semi)exceptional collections.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mikhail Gorsky (Hausdorff Research Institute for Mathematics (HIM)
)
DTSTART;VALUE=DATE-TIME:20201203T140000Z
DTEND;VALUE=DATE-TIME:20201203T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/22
DESCRIPTION:Title: Exact structures and degeneration of Hall algebras\nby Mikhail Gor
sky (Hausdorff Research Institute for Mathematics (HIM)) as part of FD Sem
inar\n\n\nAbstract\nHall algebras and various related structures play a pr
ominent role in the modern representation theory. I will explain the inter
play between different exact structures on an additive category and degene
rations of the associated Hall algebras. For the categories of representat
ions of Dynkin quivers\, this recovers degenerations of the negative part
of the corresponding quantum group. I will sketch the proofs of our result
s in the general case based on Auslander-Reiten theory. We will discuss fu
rther examples related to quantum doubles of quantum Borel subalgebras and
\, if time permits\, certain generalizations involving extriangulated cate
gories. (Based on joint work with Xin Fang.)\n
LOCATION:https://researchseminars.org/talk/fd-seminar/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Habermann (University College London (UCL))
DTSTART;VALUE=DATE-TIME:20201008T130000Z
DTEND;VALUE=DATE-TIME:20201008T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/23
DESCRIPTION:Title: Homological mirror symmetry for invertible polynomials in two variable
s\nby Matthew Habermann (University College London (UCL)) as part of F
D Seminar\n\n\nAbstract\nThe starting point for homological mirror symmetr
y for invertible polynomials is an n x n invertible matrix with non-negati
ve integer entries. To such a matrix\, as well as to its transpose\, one c
an associate polynomials. These polynomials are called invertible if they
are weighted homogeneous\, and both define isolated singularities at the o
rigin. Homological mirror symmetry for invertible polynomials is a series
of conjectures which posits the equivalence of the different flavours of F
ukaya category associated to the Lefschetz fibration defined by one polyno
mial with various flavours of graded matrix factorisations defined by the
transpose polynomial. Particular to the case of two variables is the fact
that the partially wrapped Fukaya category of a Milnor fibre corresponds t
o the derived category of modules of a gentle algebra\, and so HMS for inv
ertible polynomials in two variables allows one to study the latter catego
ry geometrically. In this talk I will explain my recent work\, part of whi
ch was done jointly with Jack Smith.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joe Grant (University of East Anglia)
DTSTART;VALUE=DATE-TIME:20201015T130000Z
DTEND;VALUE=DATE-TIME:20201015T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/24
DESCRIPTION:Title: Preprojective algebras and fractional Calabi-Yau algebras\nby Joe
Grant (University of East Anglia) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arne Mertens (Universiteit Antwerpen)
DTSTART;VALUE=DATE-TIME:20201105T140000Z
DTEND;VALUE=DATE-TIME:20201105T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/25
DESCRIPTION:Title: Linear quasi-categories as templicial modules\nby Arne Mertens (Un
iversiteit Antwerpen) as part of FD Seminar\n\n\nAbstract\nThis is joint w
ork with my supervisor Wendy Lowen. After laying out the basics of quasi-c
ategories as defined by Joyal\, we introduce a notion of linear quasi-cate
gories over a unital commutative ring. We make use of certain colax monoid
al functors\, which we call templicial modules\, as a variant of simplicia
l modules respecting the monoidal structure. It turns out that templicial
modules with a Frobenius monoidal structure are equivalent to (homological
ly) non-negatively graded dg-categories. Through this equivalence we can a
ssociate to any dg-category a linear quasi-category\, the linear dg-nerve\
, which enhances the classical dg-nerve.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ICRA2020 Research Snapshots
DTSTART;VALUE=DATE-TIME:20201112T140000Z
DTEND;VALUE=DATE-TIME:20201112T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/26
DESCRIPTION:by ICRA2020 Research Snapshots as part of FD Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ICRA2020 Research Snapshots
DTSTART;VALUE=DATE-TIME:20201119T140000Z
DTEND;VALUE=DATE-TIME:20201119T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/27
DESCRIPTION:by ICRA2020 Research Snapshots as part of FD Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ICRA2020 Research Snapshots
DTSTART;VALUE=DATE-TIME:20201126T140000Z
DTEND;VALUE=DATE-TIME:20201126T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/28
DESCRIPTION:by ICRA2020 Research Snapshots as part of FD Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Henning Krause (Universität Bielefeld)
DTSTART;VALUE=DATE-TIME:20210107T140000Z
DTEND;VALUE=DATE-TIME:20210107T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/29
DESCRIPTION:Title: The category of local representations of a finite group\nby Hennin
g Krause (Universität Bielefeld) as part of FD Seminar\n\n\nAbstract\nWe
consider modular representations of a finite group and focus for each prim
e ideal of the cohomology ring on the stable category of representations s
upported at that prime. This category is tensor triangulated\, but compact
and dualising objects do not coincide. For instance\, the tensor unit is
not compact. This is in contrast to the global category of representations
and leads to an interesting completion of the category of compact objects
. The talk presents recent progress from an ongoing collaboration with Dav
e Benson\, Srikanth Iyengar\, and Julia Pevtsova.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chrysostomos Psaroudakis (Aristotle University of Thessaloniki)
DTSTART;VALUE=DATE-TIME:20210114T140000Z
DTEND;VALUE=DATE-TIME:20210114T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/30
DESCRIPTION:by Chrysostomos Psaroudakis (Aristotle University of Thessalon
iki) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jason Lo (California State University\, Northridge (CSUN))
DTSTART;VALUE=DATE-TIME:20210121T140000Z
DTEND;VALUE=DATE-TIME:20210121T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/31
DESCRIPTION:by Jason Lo (California State University\, Northridge (CSUN))
as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Teresa Conde (Universität Stuttgart)
DTSTART;VALUE=DATE-TIME:20210128T140000Z
DTEND;VALUE=DATE-TIME:20210128T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/32
DESCRIPTION:by Teresa Conde (Universität Stuttgart) as part of FD Seminar
\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Grzegorz Bobiński (Nicolaus Copernicus University)
DTSTART;VALUE=DATE-TIME:20210204T140000Z
DTEND;VALUE=DATE-TIME:20210204T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/33
DESCRIPTION:by Grzegorz Bobiński (Nicolaus Copernicus University) as part
of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emily Barnard (DePaul University)
DTSTART;VALUE=DATE-TIME:20210211T140000Z
DTEND;VALUE=DATE-TIME:20210211T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/34
DESCRIPTION:by Emily Barnard (DePaul University) as part of FD Seminar\n\n
Abstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hipólito Treffinger (Rheinische Friedrich-Wilhelms-Universität B
onn)
DTSTART;VALUE=DATE-TIME:20210218T140000Z
DTEND;VALUE=DATE-TIME:20210218T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/35
DESCRIPTION:by Hipólito Treffinger (Rheinische Friedrich-Wilhelms-Univers
ität Bonn) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:İlke Çanakçı (Vrije Universiteit Amsterdam)
DTSTART;VALUE=DATE-TIME:20210225T140000Z
DTEND;VALUE=DATE-TIME:20210225T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/36
DESCRIPTION:by İlke Çanakçı (Vrije Universiteit Amsterdam) as part of
FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Javad Asadollahi (University of Isfahan)
DTSTART;VALUE=DATE-TIME:20210304T140000Z
DTEND;VALUE=DATE-TIME:20210304T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/37
DESCRIPTION:by Javad Asadollahi (University of Isfahan) as part of FD Semi
nar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hans Franzen (Ruhr-Universität Bochum)
DTSTART;VALUE=DATE-TIME:20210311T140000Z
DTEND;VALUE=DATE-TIME:20210311T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/38
DESCRIPTION:by Hans Franzen (Ruhr-Universität Bochum) as part of FD Semin
ar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vincent Gelinas
DTSTART;VALUE=DATE-TIME:20210318T140000Z
DTEND;VALUE=DATE-TIME:20210318T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/39
DESCRIPTION:by Vincent Gelinas as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sebastian Eckert (Universität Bielefeld)
DTSTART;VALUE=DATE-TIME:20210325T140000Z
DTEND;VALUE=DATE-TIME:20210325T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/40
DESCRIPTION:by Sebastian Eckert (Universität Bielefeld) as part of FD Sem
inar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jan Šťovíček (Charles University)
DTSTART;VALUE=DATE-TIME:20210401T130000Z
DTEND;VALUE=DATE-TIME:20210401T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/41
DESCRIPTION:by Jan Šťovíček (Charles University) as part of FD Seminar
\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Agnieszka Bodzenta-Skibińska (University of Warsaw)
DTSTART;VALUE=DATE-TIME:20210415T130000Z
DTEND;VALUE=DATE-TIME:20210415T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/42
DESCRIPTION:Title: Abelian envelopes of exact categories\nby Agnieszka Bodzenta-Skibi
ńska (University of Warsaw) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zheng Hua (University of Hong Kong)
DTSTART;VALUE=DATE-TIME:20210422T130000Z
DTEND;VALUE=DATE-TIME:20210422T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/43
DESCRIPTION:Title: Cluster categories and rational curves\nby Zheng Hua (University o
f Hong Kong) as part of FD Seminar\n\n\nAbstract\nGiven a semi-simple coll
ection of rational curves on a smooth quasi-projective 3-fold\, its multip
ointed noncommutative deformation is represented by a negatively graded DG
A $\\Gamma$. The finite dimensionality of the cohomology of $\\Gamma$ seem
s to relate to contractibility of the collection of rational curves. For C
Y 3-folds\, $\\Gamma$ is a bimodule 3CY DG algebra. If we further assume c
ontractibility then $H^0\\Gamma$ is isomorphic to the contraction algebra
of Donovan and Wemyss. And the cluster category of $\\Gamma$ is dg-equival
ent to the singularity category of the contracted space. In some sense the
CY algebra $\\Gamma$ links the deformation theory of the exceptional fibr
es and the singularity theory of the contracted space. In this talk I will
present a joint work with Bernhard Keller\, where we prove that the deriv
ed Morita type of the contraction algebra together with a canonical class
in its 0-th Hochschild homology defined via CY structure determines the an
alytic type of the singularity of the contracted space.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Magdalena Boos (Ruhr-Universität Bochum)
DTSTART;VALUE=DATE-TIME:20210429T130000Z
DTEND;VALUE=DATE-TIME:20210429T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/44
DESCRIPTION:Title: On symmetric quivers and their degenerations\nby Magdalena Boos (R
uhr-Universität Bochum) as part of FD Seminar\n\n\nAbstract\nWe introduce
the notion of a symmetric quiver as provided by Derksen and Weyman in 200
2 and discuss symmetric degenerations in this context (which correspond to
orbit closure relations in the symmetric representation variety). After m
otivating our particular interest in the latter by presenting connections
to group actions in algebraic Lie Theory\, we explain our main questions:
are symmetric degenerations induced by “usual” degenerations in the re
presentation variety of the underlying quiver? We look at (counter)example
s and recent results.\n\nThis is joint work with G. Cerulli Irelli and F.
Esposito.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Osamu Iyama (The University of Tokyo)
DTSTART;VALUE=DATE-TIME:20210513T130000Z
DTEND;VALUE=DATE-TIME:20210513T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/45
DESCRIPTION:Title: Periodic trivial extension algebras and fractionally Calabi-Yau algebr
as\nby Osamu Iyama (The University of Tokyo) as part of FD Seminar\n\n
\nAbstract\nWe study periodicity and twisted periodicity of the trivial ex
tension algebra T(A) of a finite-dimensional algebra A. We prove that (twi
sted) periodicity of the trivial extension is equivalent to A being (twist
ed) fractionally Calabi–Yau. Moreover\, twisted periodicity of T(A) is e
quivalent to the d-representation-finiteness of the r-fold trivial extensi
on algebra Tr(A) for some positive integers r and d. These results allow u
s to construct a large number of new examples of periodic as well as fract
ionally Calabi–Yau algebras\, and give answers to several open questions
. This is a joint work with Aaron Chan\, Erik Darpö and René Marczinzik.
\n
LOCATION:https://researchseminars.org/talk/fd-seminar/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gordana Todorov (Northeastern University)
DTSTART;VALUE=DATE-TIME:20210603T130000Z
DTEND;VALUE=DATE-TIME:20210603T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/46
DESCRIPTION:Title: Cluster Structures and Cluster Theories\nby Gordana Todorov (North
eastern University) as part of FD Seminar\n\n\nAbstract\n(Joint work with
Kiyoshi Igusa and Job D. Rock)\n\nI will discuss continuous cluster catego
ries\, generalizations of those\, cluster structures\, examples when only
conditions for “cluster theories”\, but not “cluster structures” (
in the sense of BIRS) are satisfied. Also relations between various cluste
r theories will be stated (some known\, some naturally expected).\n
LOCATION:https://researchseminars.org/talk/fd-seminar/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vincent Gelinas
DTSTART;VALUE=DATE-TIME:20210610T130000Z
DTEND;VALUE=DATE-TIME:20210610T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/47
DESCRIPTION:Title: Some invariants related to the finitistic dimension\nby Vincent Ge
linas as part of FD Seminar\n\n\nAbstract\nThe finitistic dimension of Art
in algebras is notoriously hard to understand. In this talk\, we’ll disc
uss an attempt to pin it down in terms of a new invariant\, defined more g
enerally over sufficiently nice Noetherian rings. Originally meant to mode
l the finitistic dimension of Iwanaga-Gorenstein rings\, it unexpectedly a
lso gave the correct answer for commutative local Noetherian rings\, Artin
algebras of radical square zero\, and (due to recent results of Ringel an
d Sen) Nakayama algebras. Given time\, we’ll also discuss links with the
notion of “finitistic” Auslander algebras recently introduced by Marc
zinzik.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Brüstle (Université de Sherbrooke)
DTSTART;VALUE=DATE-TIME:20210617T130000Z
DTEND;VALUE=DATE-TIME:20210617T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/48
DESCRIPTION:Title: On length functions for an exact category\nby Thomas Brüstle (Uni
versité de Sherbrooke) as part of FD Seminar\n\n\nAbstract\nThe notion of
an exact category has been introduced by Quillen to axiomatize homologica
l properties of abelian categories. It allows to define and study homologi
cal properties of an exact category\, and to define its derived category.
However\, it turns out that the fundamental concept of length\, as known f
or modules\, is less suitable to be studied in the context of an exact cat
egory. We aim in this talk to present some recent developments showing for
which kind of exact categories an analogue of the Jordan-Hölder property
holds\, and what one can expect from the notion of length in general. We
also present results on the lattice structure of the set of all exact stru
ctures that can be attached to a fixed additive category.\n\nSome of the p
resented results are joint work with Rose-Line Baillargeon\, Mikhail Gorsk
y\, Souheila Hassoun and Aran Tattar.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Merlin Christ (Universität Hamburg)
DTSTART;VALUE=DATE-TIME:20210722T130000Z
DTEND;VALUE=DATE-TIME:20210722T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/49
DESCRIPTION:Title: Geometric models of Ginzburg algebras via local-to-global principles\nby Merlin Christ (Universität Hamburg) as part of FD Seminar\n\n\nAbs
tract\nThe derived categories of different classes of algebras (e.g. gentl
e algebras) and dg-algebras (e.g. Ginzburg algebras of triangulated surfac
es) have recently been described in terms of surfaces\, in so-called geome
tric models. Results include the description of objects in terms of curves
in a surface and Hom’s in terms of intersections. These algebras have i
n common that they arise via gluing\, i.e. as the global sections of a con
structible cosheaf. In the talk\, we will describe the gluing construction
for (relative) Ginzburg algebras of triangulated surfaces and compare it
with the gluing construction for gentle algebras. We will then discuss how
the gluing constructions naturally lead to the geometric models of their
derived categories.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Van Nguyen (United States Naval Academy)
DTSTART;VALUE=DATE-TIME:20210506T130000Z
DTEND;VALUE=DATE-TIME:20210506T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/50
DESCRIPTION:Title: Quantum symmetries through the lens of linear algebra\nby Van Nguy
en (United States Naval Academy) as part of FD Seminar\n\n\nAbstract\nThe
McKay matrix $M_V$ records the result of tensoring the simple modules with
a finite-dimensional module $V$. In the case of finite groups\, the eigen
vectors for $M_V$ are the columns of the character table\, and the eigenva
lues come from evaluating the character of $V$ on conjugacy class represen
tatives.\n\nIn this talk\, we will explore what can be said about such eig
envectors when the McKay matrix is determined by modules over an arbitrary
finite-dimensional Hopf algebra $H$. Here\, the McKay matrix \n$M_V$ enco
des quantum symmetries coming from the actions of $H$. We prove general re
sults about $M_V$ by using the coproduct and the characters of simple and
projective $H$-modules\, and also obtain results for a different matrix th
at encodes the fusion rules for Hopf algebra $H$. We illustrate these resu
lts for the small quantum group $u_q(\\mathfrak{sl}_2)$\, where $q$ is a r
oot of unity (and generally for the Drinfeld double $D_n$ of the Taft alge
bra). In these examples\, the eigenvalues and eigenvectors for these matri
ces can be described in terms of several kinds of Chebyshev polynomials.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Martin Kalck
DTSTART;VALUE=DATE-TIME:20210624T130000Z
DTEND;VALUE=DATE-TIME:20210624T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/51
DESCRIPTION:Title: A surface and a threefold with equivalent singularity categories\n
by Martin Kalck as part of FD Seminar\n\n\nAbstract\nWe start with an intr
oduction to singularity categories and equivalences between them. In parti
cular\, we recall known results about singular equivalences between commut
ative rings\, which go back to Knörrer\, Yang\, Kawamata and a joint work
with Karmazyn. Then we explain a new singular equivalence between an affi
ne surface and an affine threefold. This seems to be the first (non-trivia
l) example of a singular equivalence involving rings of even and odd Krull
dimension.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Khrystyna Serhiyenko (University of Kentucky)
DTSTART;VALUE=DATE-TIME:20210715T130000Z
DTEND;VALUE=DATE-TIME:20210715T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/52
DESCRIPTION:Title: Maximal green sequences for string algebras\nby Khrystyna Serhiyen
ko (University of Kentucky) as part of FD Seminar\n\n\nAbstract\nMaximal g
reen sequences are certain transformations of quivers that were first intr
oduced by Keller in the context of cluster algebras. Later they were gener
alized to the setting of finite dimensional algebras\, where a maximal gre
en sequence is a finite maximal chain in the lattice of torsion classes. M
ore recently\, it was shown that these sequences are in bijection with for
ward hom-orthogonal sequences of bricks in the module category. We use the
latter approach to study existence and number of maximal green sequences
for string algebras. This is joint work with Al Garver.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Peter Jørgensen (Aarhus University)
DTSTART;VALUE=DATE-TIME:20210729T130000Z
DTEND;VALUE=DATE-TIME:20210729T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/53
DESCRIPTION:Title: Abelian subcategories of triangulated categories induced by simple min
ded systems\nby Peter Jørgensen (Aarhus University) as part of FD Sem
inar\n\n\nAbstract\nIf $k$ is a field\, $A$ a finite dimensional $k$-algeb
ra\, then the simple $A$-modules form a simple minded collection in the de
rived category $D^b(mod A)$. Their extension closure is $mod A$\; in parti
cular\, it is abelian. This situation is emulated by a general simple mind
ed collection $S$ in a suitable triangulated category $C$. In particular\,
the extension closure $\\langle S \\rangle$ is abelian\, and there is a t
ilting theory for such abelian subcategories of $C$. These statements foll
ow from $\\langle S \\rangle$ being the heart of a bounded t-structure.\n\
nIt is a defining characteristic of simple minded collections that their n
egative self extensions vanish in every degree. Relaxing this to vanishing
in degrees $\\{-w+1\, \\dots\, -1\\}$ where $w$ is a positive integer lea
ds to the rich\, parallel notion of $w$-simple minded systems\, which have
recently been the subject of vigorous interest within negative cluster ti
lting theory.\n\nIf $S$ is a $w$-simple minded system for some $w\\geq 2$\
, then $\\langle S \\rangle$ is typically not the heart of a t-structure.
However\, it is possible to prove by different means that $\\langle S \\ra
ngle$ is still abelian and that there is a tilting theory for such abelian
subcategories. We will explain the theory behind this\, which is based on
Quillen’s notion of exact categories.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ana García-Elsener (Universidad Nacional de Mar del Plata)
DTSTART;VALUE=DATE-TIME:20210701T130000Z
DTEND;VALUE=DATE-TIME:20210701T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/54
DESCRIPTION:Title: Rigid indecomposable modules in Grassmannian cluster categories\nb
y Ana García-Elsener (Universidad Nacional de Mar del Plata) as part of F
D Seminar\n\n\nAbstract\nThe coordinate ring of the Grassmannian variety o
f $k$-dimensional subspaces in $\\mathbb{C^n}$ has a cluster algebra struc
ture with Plucker relations giving rise to exchange relations. We study in
decomposable modules of the corresponding Grassmannian cluster categories
of type $(k\,n)$. Jensen\, King\, and Su have associated a Kac-Moody root
system to the category and shown that in the finite types\, rigid indecomp
osable modules correspond to roots. We provide evidence for this associati
on in the infinite types: we show that every indecomposable rank $2$ modul
e corresponds to a root of the associated root system. We also study roots
and indecomposable rank $3$ modules for the case $(3\,n)$.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kent Vashaw (Louisiana State University)
DTSTART;VALUE=DATE-TIME:20210708T130000Z
DTEND;VALUE=DATE-TIME:20210708T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/55
DESCRIPTION:Title: Noncommutative Tensor Triangular Geometry and Cohomological Support Va
rieties\nby Kent Vashaw (Louisiana State University) as part of FD Sem
inar\n\n\nAbstract\nRecently\, there has been significant interest in the
tensor product property for cohomological support varieties of Hopf algebr
as and tensor categories. We will describe a method for approaching the te
nsor product property by way of a noncommutative version of Balmer’s ten
sor triangular geometry in the general setting of a monoidal triangulated
category. We prove related properties about the collections of thick one-s
ided and two-sided ideals of the category\, and then are often able to use
the universal properties of the Balmer support to obtain applications to
cohomological supports. Examples arising from the representation theory of
Hopf algebras will be discussed throughout. This is joint work with Danie
l Nakano and Milen Yakimov.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hugh Thomas (Université du Québec à Montréal)
DTSTART;VALUE=DATE-TIME:20210902T130000Z
DTEND;VALUE=DATE-TIME:20210902T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/56
DESCRIPTION:Title: An algebraic variety related to tau-tilting theory\nby Hugh Thomas
(Université du Québec à Montréal) as part of FD Seminar\n\n\nAbstract
\nLet A be a finite-dimensional algebra of finite representation type. I w
ill describe an affine algebraic variety whose totally non-negative part r
eflects the combinatorics of the tau-tilting fan of A. Starting from a Dyn
kin quiver\, one obtains something closely related to the corresponding Fo
ck–Goncharov cluster X variety\, while in general\, points on (one compo
nent of) the variety can be given in terms of ratios of F-polynomials\; th
e upshot is that this construction can be viewed as an extension of some o
f the beautiful features of cluster algebras to a more general setting. No
netheless\, familiarity with cluster algebras will not be needed to unders
tand the talk. A conjecture related to functoriality properties of the con
struction will be discussed. This is part of a joint project with Nima Ark
ani-Hamed\, Hadleigh Frost\, Pierre-Guy Plamondon\, and Giulio Salvatori.\
n
LOCATION:https://researchseminars.org/talk/fd-seminar/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johanne Haugland (Norges teknisk-naturvitenskapelige universitet\,
NTNU)
DTSTART;VALUE=DATE-TIME:20210909T130000Z
DTEND;VALUE=DATE-TIME:20210909T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/57
DESCRIPTION:Title: Higher Koszul duality and connections with n-hereditary algebras\n
by Johanne Haugland (Norges teknisk-naturvitenskapelige universitet\, NTNU
) as part of FD Seminar\n\n\nAbstract\nWe discuss a connection between two
areas of independent interest in representation theory\, namely Koszul du
ality and higher homological algebra. This is studied through a generaliza
tion of the notion of T-Koszul algebras\, as introduced by Madsen and Gree
n–Reiten–Solberg. After giving an introduction to the relevant backgro
und material\, we present a higher version of classical Koszul duality and
sketch some applications for n-hereditary algebras. In particular\, we se
e that an important class of our generalized Koszul algebras can be charac
terized in terms of n-representation infinite algebras. As a consequence\,
we show that an algebra is n-representation infinite if and only if its t
rivial extension is (n+1)-Koszul with respect to its degree 0 part. A gene
ralized notion of almost Koszulity in the sense of Brenner–Butler–King
yields similar results in the n-representation finite case. \n\nThis talk
is based on joint work with Mads H. Sandøy.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Sistko (Manhattan College)
DTSTART;VALUE=DATE-TIME:20210916T130000Z
DTEND;VALUE=DATE-TIME:20210916T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/58
DESCRIPTION:Title: F1 Representations and Hall Algebras\nby Alexander Sistko (Manhatt
an College) as part of FD Seminar\n\n\nAbstract\nFor any quiver Q\, one ca
n associate a category of Q-representations over F1\, the so-called “fie
ld with one element.” This category\, and its associated Ringel-Hall alg
ebra\, retain many features of representations over fields while exhibitin
g interesting differences. In this talk\, we discuss recent advances in th
e study of F1-representations and their Hall algebras. After an overview o
f the fundamental background\, we describe how F1-representations may be s
tudied via coefficient quivers. This approach yields results on representa
tion type over F1 and new insights into the associated Hall algebras. With
the remaining time\, we discuss an ongoing project which applies F1-repre
sentation theory to compute the Euler characteristics of certain quiver Gr
assmannians. This is joint work with Jaiung Jun.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Steffen Oppermann (Norges teknisk-naturvitenskapelige universitet\
, NTNU)
DTSTART;VALUE=DATE-TIME:20210923T130000Z
DTEND;VALUE=DATE-TIME:20210923T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/59
DESCRIPTION:Title: Rank decompositions and associated exact categories for multi-paramete
r persistence modules\nby Steffen Oppermann (Norges teknisk-naturviten
skapelige universitet\, NTNU) as part of FD Seminar\n\n\nAbstract\nThe mot
ivation for the work I am going to speak about comes from a recent field o
f application of representation theory: the study of persistent homology i
n topological data analysis.\n\nI will try to explain how and why one migh
t turn data into a quiver representation. Most classically this will be a
representation of a linearly ordered quiver of type A. Such a representati
on can be depicted as a collection of line segments\, corresponding to the
supports of the indecomposable summands. This depiction is known as a “
bar code”. One interprets the results by considering the longest bars mo
st significant.\n\nIn many applications\, it would be natural to consider
multiple parameters\, equivalently representation of tensor products of mu
ltiple type A quivers. These algebras are wild in almost all cases\, and i
ndecomposables are not determined by their support as in the one parameter
case.\n\nThe original part of my talk will be based on joint work with Ma
gnus Botnan and Steve Oudot. We introduce a candidate for a bar code of a
2-parameter persistence module\, and observe that it is closely related to
an exact structure on the representation category.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Timothy Logvinenko (Cardiff University)
DTSTART;VALUE=DATE-TIME:20210930T130000Z
DTEND;VALUE=DATE-TIME:20210930T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/60
DESCRIPTION:Title: The Heisenberg category of a category\nby Timothy Logvinenko (Card
iff University) as part of FD Seminar\n\n\nAbstract\nIn 90s Nakajima and G
rojnowski identified the total cohomology of the Hilbert schemes of points
on a smooth projective surface with the Fock space representation of the
Heisenberg algebra associated to its cohomology lattice. Later\, Krug lift
ed this to derived categories\nand generalised it to the symmetric quotien
t stacks of any smooth projective variety.\n\nOn the other hand\, Khovanov
introduced a categorification of the free boson Heisenberg algebra\, i.e.
the one associated to the rank 1 lattice. It is a monoidal category whose
\nmorphisms are described by a certain planar diagram calculus which categ
orifies the Heisenberg relations. A similar categorification was construct
ed by Cautis and Licata for the Heisenberg algebras of ADE type root latti
ces.\n\nWe show how to associate the Heisenberg 2-category to any smooth a
nd proper DG category and then define its Fock space 2-representation. Thi
s construction unifies all the results above and extends them to what can
be viewed as the generality of arbitrary noncommutative smooth and proper
schemes.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Martin Herschend (Uppsala University)
DTSTART;VALUE=DATE-TIME:20211007T130000Z
DTEND;VALUE=DATE-TIME:20211007T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/61
DESCRIPTION:Title: Double covers of quiver Heisenberg algebras as higher preprojective al
gebras\nby Martin Herschend (Uppsala University) as part of FD Seminar
\n\n\nAbstract\nLet Q be a finite acyclic quiver. In my talk I will discus
s several algebras associated to Q and how they are related. As a starting
point we’ll consider the path algebra of Q and how its representation t
heory is reflected in homological properties of the preprojective algebra
of Q. One immediate connection is that the preprojective algebra is graded
and its degree zero part is the path algebra.\n\nNext we turn to the quiv
er Heisenberg algebra of Q. This algebra is a particular case of the centr
al extensions of preprojective algebras introduced by Etingof-Rains. It ha
s many similar properties to the preprojective algebra. Finally\, we will
consider a certain double cover of the quiver Heisenberg algebra\, more pr
ecisely its second quasi-Veronese algebra. This algebra is also graded and
turns out to be a higher preprojective algebra of its degree zero part B.
The algebra B has many similarities with the original path algebra. It ha
s global dimension 2 and is 2-hereditary algebra in the sense of Iyama’s
higher dimensional Auslander-Reiten theory.\n\nThis talk is based on ongo
ing joint work with Hiroyuki Minamoto.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yann Palu (Université UPJV Amiens)
DTSTART;VALUE=DATE-TIME:20211014T130000Z
DTEND;VALUE=DATE-TIME:20211014T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/62
DESCRIPTION:Title: Mutation in hereditary extriangulated categories\nby Yann Palu (Un
iversité UPJV Amiens) as part of FD Seminar\n\n\nAbstract\nMotivated by t
he categorification of cluster algebras\, Buan–Marsh–Reineke–Reiten
–Todorov introduced a theory of mutation for cluster-tilting objects in
certain 2-Calabi–Yau triangulated categories. This lead to many variatio
ns or generalisations\, such as tau-tilting\, 2-term silting or relative t
ilting.\n\nThe point-of-view of extriangulated categories\, introduced in
collaboration with Hiroyuki Nakaoka\, turns out to be relevant for the stu
dy of mutations. Indeed\, most mutation theories arising in representation
theory can be related to the existence of certain “good” extriangulat
ed structures. This is the point that I will try and make in this talk\, b
y introducing the notion of a 0-Auslander extriangulated category.\n\nThis
is based on joint works with Mikhail Gorsky\, Hiroyuki Nakaoka\, Arnau Pa
drol\, Vincent Pilaud and Pierre-Guy Plamondon.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hiroki Matsui (Tokushima University)
DTSTART;VALUE=DATE-TIME:20211021T130000Z
DTEND;VALUE=DATE-TIME:20211021T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/63
DESCRIPTION:Title: Prime thick subcategories of derived categories associated with noethe
rian schemes\nby Hiroki Matsui (Tokushima University) as part of FD Se
minar\n\n\nAbstract\nIn 2005\, Balmer introduced the notion of a prime thi
ck tensor ideal for a tensor triangulated category T as an analogous conce
pt to a prime ideal of a commutative ring. Using prime thick tensor ideals
\, Balmer established the epoch-making theory so-called the tensor-triangu
lar geometry which allows us to study T by commutative-algebraic/algebro-g
eometric approaches. On the other hand\, recently I have introduced the no
tion of prime thick subcategories to develop a similar theory to the tenso
r-triangular geometry for tensor triangulated categories without tensor st
ructures. In this talk\, we study prime thick subcategories of the perfect
derived category D^perf(X)\, the bounded derived category D^b(X)\, and th
e singularity category D^sg(X) of a noetherian scheme X. Especially\, we g
ive a characterization of a point x of X to be a complete intersection or
a hypersurface in terms of prime thick subcategories of such derived categ
ories.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Calin Chindris (University of Missouri)
DTSTART;VALUE=DATE-TIME:20211028T130000Z
DTEND;VALUE=DATE-TIME:20211028T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/64
DESCRIPTION:Title: Sigma-critical quiver representations and applications to the Paulsen
Problem in Frame Theory\nby Calin Chindris (University of Missouri) as
part of FD Seminar\n\n\nAbstract\nSigma-critical representations are quiv
er representations that satisfy certain matrix equations. They arise natur
ally in the context of the Kempf-Ness theorem on closed orbits in Invarian
t Theory. After introducing all the relevant concepts\, I will first descr
ibe a result that gives necessary and sufficient conditions for the orbit
of a representation to contain a sigma-critical representation. I will the
n explain how this result can be used to solve the Paulsen Problem for mat
rix frames. This is based on joint work with Jasim Ismaeel.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/64/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Changchang Xi (Capital Normal University)
DTSTART;VALUE=DATE-TIME:20211104T140000Z
DTEND;VALUE=DATE-TIME:20211104T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/65
DESCRIPTION:Title: Symmetric subcategories and good tilting modules\nby Changchang Xi
(Capital Normal University) as part of FD Seminar\n\n\nAbstract\nTilting
modules have played an important role in representation theory of algebras
. Especially\, infinitely generated tilting modules provide completely dif
ferent features. In this case\, recollements of triangulated categories in
the sense of Beilinson-Bernstein-Deligne enter into the play. In this tal
k\, we introduce symmetric subcategories and show that\, for any good tilt
ing module over an algebra\, the derived category of the endomorphism alge
bra of the tilting module is always a recollement of the derived categorie
s of the given algebra and a symmetric subcategory of a module category. E
xplicit examples of symmetric subcategories associated to 2-good tilting m
odules over commutative Gorenstein rings are presented. This talk reports
a joint work with Hongxing Chen.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/65/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emine Yıldırım (Isaac Newton Institute for Mathematical Science
s and University of Cambridg)
DTSTART;VALUE=DATE-TIME:20211111T140000Z
DTEND;VALUE=DATE-TIME:20211111T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/66
DESCRIPTION:Title: Periodic actions on distributive lattices and counterparts in algebra<
/a>\nby Emine Yıldırım (Isaac Newton Institute for Mathematical Science
s and University of Cambridg) as part of FD Seminar\n\n\nAbstract\nLet L b
e a distributive lattice and A be its incidence algebra. There is a celebr
ated combinatorial action on posets called “rowmotion”. Thanks to a re
sult of Iyama-Marczinzik\, we can think of this combinatorial action as th
e grade bijection defined on the algebra A. On the other hand\, the Coxete
r transformation plays an important role in representation theory of algeb
ras and in some cases it shows some periodicity. The periodicity of the Co
xeter transformation is motivated by the fractionally Calabi-Yau property
of a certain category. Motivated by these\, we show that the composition o
f the rowmotion and the Coxeter transformation is periodic for the algebra
A in a joint work with René Marczinzik and Hugh Thomas.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/66/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sira Gratz (University of Glasgow)
DTSTART;VALUE=DATE-TIME:20211118T140000Z
DTEND;VALUE=DATE-TIME:20211118T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/67
DESCRIPTION:Title: Thick Subcategories and Lattices\nby Sira Gratz (University of Gla
sgow) as part of FD Seminar\n\n\nAbstract\nThe computation of lattices of
thick subcategories has emerged as a popular topic and serves as a more ac
hievable analogue of classifying objects. Often one understands such latti
ces by describing them in terms of some associated topological space. Howe
ver\, in many representation theoretic examples this is not possible. I’
ll explain what the obstruction is and mention work in progress aimed at a
ddressing this issue.\n\nThis talk is based on joint work with Greg Steven
son.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/67/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Federico Barbacovi (University College London)
DTSTART;VALUE=DATE-TIME:20211125T140000Z
DTEND;VALUE=DATE-TIME:20211125T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/68
DESCRIPTION:Title: Dynamics in triangulated categories\nby Federico Barbacovi (Univer
sity College London) as part of FD Seminar\n\n\nAbstract\nIn topology a dy
namical system is given by a couple $(X\, f)$\, where $X$ is a topological
space and $f : X \\rightarrow X$ is a continuous map. Dimitrov — Haiden
— Katzarkov — Kontsevich generalised this notion to that of a categor
ical dynamical system. To measure the complexity of such system\, they als
o introduced the concept of categorical entropy. A famous theorem of Gromo
v and Yomdin relates the topological entropy of a holomorphic automorphism
of a complex manifold with the action of the automorphism in cohomology.
In this talk I will report on joint work with Jongmyeong Kim in which we p
rovide a sufficient condition that ensures that (a weaker version of) an a
nalogue theorem holds in categorical dynamics.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/68/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Constanze Roitzheim (University of Kent)
DTSTART;VALUE=DATE-TIME:20211202T140000Z
DTEND;VALUE=DATE-TIME:20211202T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/69
DESCRIPTION:Title: Homotopy theory of finite total orders\, trees and chicken feet\nb
y Constanze Roitzheim (University of Kent) as part of FD Seminar\n\n\nAbst
ract\nA transfer system is a graph on a lattice satisfying certain restric
tion and composition properties. They were first studied on the lattice of
subgroups of a finite group in order to examine equivariant homotopy comm
utativity\, which then unlocked a wealth of links to combinatorial methods
. On a finite total order [n]\, transfer systems can be used to classify d
ifferent homotopy theories on [n]. The talk will involve plenty of example
s and not assume any background knowledge.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/69/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raquel Coelho Simões (Lancaster University)
DTSTART;VALUE=DATE-TIME:20211209T140000Z
DTEND;VALUE=DATE-TIME:20211209T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/70
DESCRIPTION:Title: From gentle to string algebras: a geometric model\nby Raquel Coelh
o Simões (Lancaster University) as part of FD Seminar\n\n\nAbstract\nGeom
etric models associated to triangulations of Riemann surfaces arose in the
context of cluster algebras and have since been used as an important tool
to study representation theory of algebras and provide connections with a
lgebraic geometry and symplectic geometry.\n\nSignificant applications of
geometric models include a description of extensions and a classification
of support tau-tilting modules over gentle algebras. Gentle algebras are a
particular subclass of string algebras\, which are of tame representation
type\, meaning it is often possible to get a global understanding of thei
r representation theory.\n\nIn this talk I will describe the module catego
ry of a gentle algebra via partial triangulations of unpunctured surfaces
and explain how to extend this model to a geometric model of the module ca
tegory of any string algebra. This is based on joint work in progress with
Karin Baur.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/70/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Wemyss (University of Glasgow)
DTSTART;VALUE=DATE-TIME:20211216T140000Z
DTEND;VALUE=DATE-TIME:20211216T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/71
DESCRIPTION:Title: Local Normal Forms of Noncommutative Functions\nby Michael Wemyss
(University of Glasgow) as part of FD Seminar\n\n\nAbstract\nIn algebraic
terms\, the purpose of the talk is to classify finite dimensional Jacobi a
lgebras arising on the d-loop quiver. The surprising thing is that a clas
sification should exist at all\, and it is even more surprising that ADE e
nters. I will spend most of my time explaining what the algebras are\, wh
y they classify\, and how to intrinsically extract ADE information from th
em. I will also say a little on why this should be viewed as an extension
of classical singularity theory\, since many of the ideas are inspired by
Arnold and others. At the end\, I’ll briefly explain why I’m really
interested in this problem\, the connection with different quivers\, and t
he applications of the above classification to curve counting and biration
al geometry. This is all joint work with Gavin Brown.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/71/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Catharina Stroppel (University of Bonn)
DTSTART;VALUE=DATE-TIME:20220113T140000Z
DTEND;VALUE=DATE-TIME:20220113T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/72
DESCRIPTION:Title: Weight structures and (geometric) representation theory\nby Cathar
ina Stroppel (University of Bonn) as part of FD Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/72/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jon Woolf (University of Liverpool)
DTSTART;VALUE=DATE-TIME:20220120T140000Z
DTEND;VALUE=DATE-TIME:20220120T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/73
DESCRIPTION:Title: Bridgeland stability conditions with massless objects\nby Jon Wool
f (University of Liverpool) as part of FD Seminar\n\n\nAbstract\nThe Bridg
eland stability space of a triangulated category is a non-compact complex
manifold with a wall-and-chamber structure capturing interesting aspects o
f the category’s structure.\n\nI will describe joint work with Broomhead
\, Pauksztello and Ploog in which we partially compactify the stability sp
ace by allowing `degenerate’ stability conditions with massless objects.
\n\nOne reason this is interesting is that the added boundary points are c
losely related to the walls. I will illustrate this connection in low-dime
nsional examples arising from quivers with two vertices.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/73/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francesco Genovese (Charles University)
DTSTART;VALUE=DATE-TIME:20220127T140000Z
DTEND;VALUE=DATE-TIME:20220127T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/74
DESCRIPTION:Title: A derived Gabriel-Popescu theorem for t-structures\nby Francesco G
enovese (Charles University) as part of FD Seminar\n\n\nAbstract\nThe Gabr
iel-Popescu theorem exhibits any Grothendieck abelian category as an exact
localization of a category of modules over a suitable ring. Generalizing
to the derived framework\, we replace abelian categories with (enhanced) t
riangulated categories endowed with a t-structure. Such categories\, under
appropriate “Grothendieck-like” assumptions\, can be exhibited as t-e
xact quotients of derived categories of suitable dg-algebras concentrated
in nonpositive degrees\, hence yielding a “derived Gabriel-Popescu theor
em”. In this talk\, we describe a proof of this result which exploits th
e underlying philosophy that “(enhanced) triangulated categories with t-
structures really behave like abelian categories”. We shall encounter su
itably defined “derived epi-mono factorizations” and derived injective
objects. This is joint work with Julia Ramos González.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/74/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alfredo Nájera Chávez (Universidad Nacional Autónoma de México
)
DTSTART;VALUE=DATE-TIME:20220203T140000Z
DTEND;VALUE=DATE-TIME:20220203T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/75
DESCRIPTION:Title: Deformation theory for finite cluster complexes\nby Alfredo Nájer
a Chávez (Universidad Nacional Autónoma de México) as part of FD Semina
r\n\n\nAbstract\nCluster complexes are a certain class of simplicial compl
exes that naturally arise in the theory of cluster algebras. They codify a
wealth of fundamental information about cluster algebras. The purpose of
this talk is to elaborate on a geometric relationship between cluster alge
bras and cluster complexes. In vague words this relationship is the follow
ing: cluster algebras of finite cluster type with universal coefficients m
ay be obtained via a torus action on a Hilbert scheme. In particular\, we
will discuss the deformation theory of the Stanley-Reisner ring associated
to a finite cluster complex and present some applications related to the
Gröbner theory of the ideal of relations among cluster and frozen variabl
es of a cluster algebra of finite cluster type. Time permitting I will ela
borate on how to generalize this approach to the context of tau-tilting fi
nite algebras. This is based on a joint project with Nathan Ilten and Hipo
lito Treffinger whose first outcome is the preprint arXiv:2111.02566.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/75/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tsutomu Nakamura (The University of Tokyo)
DTSTART;VALUE=DATE-TIME:20220210T140000Z
DTEND;VALUE=DATE-TIME:20220210T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/76
DESCRIPTION:Title: The definable subcategory induced by a large canonical module\nby
Tsutomu Nakamura (The University of Tokyo) as part of FD Seminar\n\n\nAbst
ract\nAuslander and Buchweitz (1989) showed that the class of maximal Cohe
n-Macaulay modules over a Cohen-Macaulay local ring with a canonical modul
e is part of a complete cotorsion pair in the category of finitely generat
ed modules. As shown by Miyachi (1998)\, this fact holds more generally fo
r an R-order over a Cohen-Macaulay ring R with a (pointwise) canonical mod
ule. On the other hand\, Holm (2017) established a perfect cotorsion pair
(X\, Y) in the category of all modules over a Cohen-Macaulay local ring wi
th a canonical module such that X is the smallest definable subcategory co
ntaining all maximal Cohen-Macaulay modules. This result was deduced by sh
owing a Govorov-Lazard type result for X\, and the modules in X are those
called weak balanced big Cohen-Macaulay. In my talk\, I will suggest an in
finitely generated version of a canonical module\, and explain how this co
ncept makes sense to generalize Holm’s results to a non-commutative and
non-local setup like Miyachi’s work. It is also possible to partly avoid
the existence of a canonical module\, so that some results on balanced bi
g Cohen-Macaulay approximation due to Simon (2009) and Holm (2017) can be
unified. This work is inspired by ongoing joint work with Michal Hrbek and
Jan Stovicek about large (co)tilting complexes over a commutative noether
ian ring\, and related to recent joint work with Ryo Kanda about flat coto
rsion modules over Noether algebras.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/76/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexei Latyntsev (University of Oxford)
DTSTART;VALUE=DATE-TIME:20220217T140000Z
DTEND;VALUE=DATE-TIME:20220217T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/77
DESCRIPTION:Title: Quantum vertex algebras and cohomological Hall algebras\nby Alexei
Latyntsev (University of Oxford) as part of FD Seminar\n\n\nAbstract\nThe
re is an extremely rich history of interaction between string theory and t
he mathematics of moduli spaces\, for instance cohomological Hall algebras
/algebras of BPS states\, or vertex/chiral algebras.\n\nIn this talk\, I w
ill explain a link between two of these: Joyce’s vertex algebras attache
d to the moduli stack of objects in an abelian category\, and one dimensio
nal CoHAs. This is based on my recent paper 2110.14356\, whose main result
says that the cohomologies of such stacks are “quantum vertex algebras
”: the factorisation/vertex analogues of quasitriangular bialgebras. The
main technical tool is a “bivariant” Euler class which makes torus lo
calisation work in this context. I will discuss applications of these tech
niques to CoHAs of coherent sheaves on a curve and future directions.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/77/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Janina C. Letz (Universität Bielefeld)
DTSTART;VALUE=DATE-TIME:20220224T140000Z
DTEND;VALUE=DATE-TIME:20220224T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/78
DESCRIPTION:by Janina C. Letz (Universität Bielefeld) as part of FD Semin
ar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/78/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhengfang Wang (Universität Stuttgart)
DTSTART;VALUE=DATE-TIME:20220303T140000Z
DTEND;VALUE=DATE-TIME:20220303T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/79
DESCRIPTION:by Zhengfang Wang (Universität Stuttgart) as part of FD Semin
ar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/fd-seminar/79/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna Schenfisch (Montana State University)
DTSTART;VALUE=DATE-TIME:20220310T140000Z
DTEND;VALUE=DATE-TIME:20220310T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/80
DESCRIPTION:Title: Algebraic K-Theory of Zig-Zag Persistence Modules\nby Anna Schenfi
sch (Montana State University) as part of FD Seminar\n\n\nAbstract\nIn thi
s talk\, we will first see how persistence modules (a primary tool in topo
logical data analysis) have a natural home in the setting of stratified sp
aces and constructible cosheaves. In particular\, we focus on zig-zag modu
les\, which correspond to one-parameter filtrations. We then outline how t
he algebraic K-theory of zig-zag modules can be computed via an additivity
result\, aided by an equivalence between the category of zig-zag modules
and the combinatorial entrance path category on a stratified $\\mathbb{R}$
. Once equipped with the K-theory of zig-zag modules\, we see other one-pa
rameter topological summaries (such as Euler characteristic curves) as cla
sses of $K_0$.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/80/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuta Kimura (The University of Tokyo)
DTSTART;VALUE=DATE-TIME:20220317T140000Z
DTEND;VALUE=DATE-TIME:20220317T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/81
DESCRIPTION:Title: Classifying torsion classes of Noetherian algebras\nby Yuta Kimura
(The University of Tokyo) as part of FD Seminar\n\n\nAbstract\nLet R be a
commutative Noetherian ring. A Noetherian algebra A is an R-algebra which
is finitely generated as an R-module. In this talk\, we study classificat
ion problem of torsion classes and related subcategories of the category m
od A of finitely generated A-modules. In the case where R is a field\, the
re are many studies of subcategories of mod A. τ-tilting modules\, introd
uced by Adachi-Iyama-Reiten\, play a central role in the recent developmen
t of such studies. We see that silting modules also play an important role
for classification problem of torsion classes of Noetherian algebras. In
the case where A is commutative\, Serre subcategories\, torsion classes an
d torsionfree classes are classified by using subsets of the prime spectru
m of R by Gabriel\, Stanley-Wang and Takahashi. We see that our results re
cover their results. This is joint work with Osamu Iyama.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/81/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Charley Cummings (University of Bristol)
DTSTART;VALUE=DATE-TIME:20220324T140000Z
DTEND;VALUE=DATE-TIME:20220324T150000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/82
DESCRIPTION:Title: Left-right symmetry of the finitistic dimension\nby Charley Cummin
gs (University of Bristol) as part of FD Seminar\n\n\nAbstract\nThe finiti
stic dimension conjecture is the assertion that the finitistic dimension o
f a finite dimensional algebra is finite. This dimension can be defined in
terms of left or right modules. In general\, the left and right finitisti
c dimensions of an algebra are not equal\, but it is unknown if the finite
ness of the two dimensions is connected. In this talk\, we will translate
the conjecture into a question about the connection between the left and r
ight finitistic dimensions of an algebra using quiver operations.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/82/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Charlie Beil (University of Graz)
DTSTART;VALUE=DATE-TIME:20220331T130000Z
DTEND;VALUE=DATE-TIME:20220331T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/83
DESCRIPTION:Title: Dimer quivers on genus g surfaces and noncommutative desingularization
s\nby Charlie Beil (University of Graz) as part of FD Seminar\n\n\nAbs
tract\nA dimer algebra is a type of Jacobian algebra whose quiver $Q$ embe
ds in a surface $S$\, such that each connected component of $S\\backslash
Q$ is simply connected and bounded by an oriented cycle of $Q$. It was sh
own in 2009 that noetherian dimer algebras on a torus are noncommutative d
esingularizations of their centers\; in particular\, they are ‘homologic
ally smooth’ endomorphism rings. On higher genus surfaces\, however\, th
ese nice properties disappear. I will introduce special quotients of dimer
algebras\, called ‘ghor algebras’\, where the relations come from the
quiver’s perfect matchings rather than a potential. On a torus\, a dime
r algebra coincides with its ghor algebra if and only if it is noetherian\
, whereas ghor algebras are almost never noetherian on higher genus surfac
es. Nevertheless\, I will describe how a ghor algebra\, on any genus gg su
rface\, may be viewed as a noncommutative desingularization of its center.
This is joint work with Karin Baur.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/83/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir Dotsenko (University of Strasbourg)
DTSTART;VALUE=DATE-TIME:20220407T130000Z
DTEND;VALUE=DATE-TIME:20220407T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/84
DESCRIPTION:Title: Rational homotopy type of the moduli space of stable rational curves\nby Vladimir Dotsenko (University of Strasbourg) as part of FD Seminar\
n\n\nAbstract\nIn 2004\, Manin asked whether the cohomology of the moduli
space of stable rational curves with n marked points (= the Deligne-Mumfor
d compactification of the moduli space of smooth genus zero curves with n
marked points) is a Koszul algebra. This question remained open since. I s
hall present a solution to it\, proving that the answer is positive for al
l n. An immediate consequence of my result is an explicit description of t
he rational homotopy Lie algebras of these spaces by generators and relati
ons. Time permitting\, I shall discuss some generalizations and modificati
ons of this result.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/84/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Barbara Giunti (Graz University of Technology)
DTSTART;VALUE=DATE-TIME:20220414T130000Z
DTEND;VALUE=DATE-TIME:20220414T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/85
DESCRIPTION:Title: Persistence modules and amplitudes\nby Barbara Giunti (Graz Univer
sity of Technology) as part of FD Seminar\n\n\nAbstract\nPersistence theor
y is a powerful branch of Topological Data Analysis with many applications
. In this seminar\, I will briefly introduce it\, presupposing no previous
knowledge of the topic. In particular\, I will discuss some finiteness co
nditions on persistence modules. I will then introduce amplitudes\, a spec
ial type of invariants that capture the idea of ‘‘size of persistence
’’. Amplitudes can be defined on any abelian category and are particul
arly useful in the so-called multiparameter persistence\, where there exis
ts no discrete complete invariant. I will present some examples of amplitu
des and discuss some of their properties.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/85/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sota Asai (Osaka University)
DTSTART;VALUE=DATE-TIME:20220421T130000Z
DTEND;VALUE=DATE-TIME:20220421T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/86
DESCRIPTION:Title: TF equivalence classes constructed from canonical decompositions\n
by Sota Asai (Osaka University) as part of FD Seminar\n\n\nAbstract\nThis
talk is based on joint work with Osamu Iyama. Let $A$ be a finite dimensio
nal algebra over an algebraically closed field. Brüstle-Smith-Treffinger
introduced a wall-chamber structure on the real Grothendieck group $K_0(\\
operatorname{proj} A)_R$ via stability conditions of King. It is strongly
related to TF equivalence\, which is an equivalence relation on $K_0(\\ope
ratorname{proj} A)_R$ defined by numerical torsion pairs of Baumann-Kamnit
zer-Tingley. Thanks to results by Yurikusa and Brüstle-Smith-Treffinger\,
I showed that the $g$-vector cone $C^+(U)$ associated to each 2-term pres
ilting complex $U$ in $K^b(\\operatorname{proj} A)$ is a TF equivalence cl
ass in my previous study\, but we cannot obtain all TF equivalence classes
in this way unless $A$ is $\\tau$-tilting finite. In this joint work with
Iyama\, we obtained a generalization of this construction of TF equivalen
ce classes by using canonical decompositions of elements in $K_0(\\operato
rname{proj} A)$ introduced by Derksen-Fei in the case that $A$ satisfies t
he condition called EE-tameness. I will talk about this result.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/86/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Asilata Bapat (The Australian National University)
DTSTART;VALUE=DATE-TIME:20220428T130000Z
DTEND;VALUE=DATE-TIME:20220428T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/87
DESCRIPTION:Title: Bridgeland stability conditions\, spherical objects\, and autoequivale
nces\nby Asilata Bapat (The Australian National University) as part of
FD Seminar\n\n\nAbstract\nConsider the space of Bridgeland stability cond
itions of a suitably nice triangulated category. Autoequivalences of the t
riangulated category act on the space of stability conditions. Fixing a st
ability condition imposes extra combinatorial structure on the category\,
that can be used to study the group of autoequivalences in various differe
nt ways. This talk will showcase some of the fascinating structure that em
erges via this idea\, particularly for 2-Calabi–Yau categories associate
d to quivers. This is based on joint work with Anand Deopurkar and Anthony
M. Licata.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/87/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yu Qiu (Tsinghua University)
DTSTART;VALUE=DATE-TIME:20220505T130000Z
DTEND;VALUE=DATE-TIME:20220505T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/88
DESCRIPTION:Title: Geometric classification of totally stable stability spaces\nby Yu
Qiu (Tsinghua University) as part of FD Seminar\n\n\nAbstract\nWe constru
ct a geometric model for the root category of any Dynkin diagram $Q$\, whi
ch is an $h$-gon $V$ with cores\, where $h$ is the Coxeter number. As an a
pplication\, we classify all spaces $ToSt(D)$ of totally stable stability
conditions on triangulated categories $D$\, where $D$ must be of the form
$D^b(Q)$. More precisely\, we prove that $ToStD^b(Q)/C$ is isomorphic to t
he moduli spaces of stable $h$-gons of type $Q$. In particular\, an $h$-go
n $V$ of type $D_n$ is a centrally symmetric doubly punctured $2(n−1)$-g
on. $V$ is stable if it is convex and the punctures are inside the level-$
(n−2)$ diagonal-gon. Another interesting case is $E_6$\, where the (stab
le) $12$-gon can be realized as a pair of planar tiling pattern. This is a
joint work with Xiaoting Zhang.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/88/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Markus Reineke (Ruhr-Universität Bochum)
DTSTART;VALUE=DATE-TIME:20220519T130000Z
DTEND;VALUE=DATE-TIME:20220519T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/89
DESCRIPTION:Title: Dimension expanders via quiver representations\nby Markus Reineke
(Ruhr-Universität Bochum) as part of FD Seminar\n\n\nAbstract\nDimension
expanders\, introduced by Wigderson and Lubotzky-Zelmanov\, are a linear a
lgebra analogue of the notion of expander graphs. We interpret this notion
in terms of quiver representations\, as a quantitative variant of stabilt
y. We use Schofield’s recursive description of general subrepresentation
s to re-derive existence of dimension expanders and to determine optimal e
xpansion coefficients.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/89/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tiago Cruz (Universität Stuttgart)
DTSTART;VALUE=DATE-TIME:20220512T130000Z
DTEND;VALUE=DATE-TIME:20220512T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/90
DESCRIPTION:Title: Relative dominant dimension and quasi-hereditary covers\nby Tiago
Cruz (Universität Stuttgart) as part of FD Seminar\n\n\nAbstract\nEvery f
inite-dimensional algebra can be written as the endomorphism algebra of a
projective module over a quasi-hereditary algebra. Moreover\, every finite
-dimensional algebra over an algebraically closed field admits a (split) q
uasi-hereditary cover in the sense of Rouquier. So we may wonder how close
ly connected the module category of a finite-dimensional algebra is to the
module category of one of its quasi-hereditary covers.\n\nIn this talk\,
we discuss how a generalisation of dominant dimension can be used as a too
l to measure the quality of (split) quasi-hereditary covers of Noetherian
algebras and how it can be used to construct new quasi-hereditary covers.\
n
LOCATION:https://researchseminars.org/talk/fd-seminar/90/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francesco Sentieri (Università degli Studi di Verona)
DTSTART;VALUE=DATE-TIME:20220526T130000Z
DTEND;VALUE=DATE-TIME:20220526T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/91
DESCRIPTION:Title: Wide subcategories obtained from cosilting pairs\nby Francesco Sen
tieri (Università degli Studi di Verona) as part of FD Seminar\n\n\nAbstr
act\nIngalls and Thomas introduced a construction relating torsion pairs a
nd wide subcategories in the context of finite-dimensional modules over he
reditary algebras. Their work was later generalized by Marks and Stovicek
to arbitrary algebras. We apply this construction to cosilting torsion pai
rs in the category of all modules and give a description of the resulting
wide subcategories as some generalized perpendicular categories. We show t
hat all the wide subcategories we obtain are coreflective and discuss the
case in which they are bireflective. We conclude with an application to th
e study of torsion pairs in the category of finite-dimensional modules. Th
is is joint work with Lidia Angeleri.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/91/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rene Marczinzik
DTSTART;VALUE=DATE-TIME:20220602T130000Z
DTEND;VALUE=DATE-TIME:20220602T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/92
DESCRIPTION:Title: Dominant Auslander regular algebras and minimal Auslander-Cohen-Macaul
ay algebras\nby Rene Marczinzik as part of FD Seminar\n\n\nAbstract\nW
e introduce dominant Auslander regular algebras and minimal Auslander-Cohe
n-Macaulay algebras as a generalisation of higher Auslander algebras. As a
n application we show how those two new classes of algebras can be used to
answer a question by Green and another question by Auslander and Reiten.
This is joint work in progress with Aaron Chan and Osamu Iyama.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/92/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Charles Paquette (Royal Military College of Canada)
DTSTART;VALUE=DATE-TIME:20220609T130000Z
DTEND;VALUE=DATE-TIME:20220609T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/93
DESCRIPTION:Title: Free products of semi-simple algebras via quivers\nby Charles Paqu
ette (Royal Military College of Canada) as part of FD Seminar\n\n\nAbstrac
t\nWe will see how quiver representation theory and stability allow us to
understand the (finite dimensional) representation theory of a free produc
t of semi-simple (associative) k-algebras. In particular\, we will study t
he simple modules and modules in general position. We will see that a modu
le in general position is always semisimple\, and give an explicit numeral
equation to decide when it is simple. If time permits\, we will comment o
n the representation type (tame\, wild) and discuss how to use moduli spac
es of quivers to compute the number of parameters for the simple modules i
n a given dimension. This is joint work with A. Buchanan\, I. Dimitrov\, O
. Grace\, D. Wehlau and T. Xu.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/93/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicholas Williams (The University of Tokyo)
DTSTART;VALUE=DATE-TIME:20220616T130000Z
DTEND;VALUE=DATE-TIME:20220616T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/94
DESCRIPTION:Title: Mutating cluster-tilting objects in (d + 2)-angulated cluster categori
es\nby Nicholas Williams (The University of Tokyo) as part of FD Semin
ar\n\n\nAbstract\nOppermann and Thomas introduced the (d + 2)-angulated cl
uster category to generalise the classical cluster category to higher homo
logical algebra. A great difficulty that arises in these categories is tha
t cluster-tilting objects are no longer mutable at every summand\, in cont
rast to the classical setting. In this talk we give two new ways of unders
tanding mutability in these higher cluster categories: one from an algebra
ic perspective\, and the other from a combinatorial perspective\, for the
particular case of the higher Auslander algebras of type A.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/94/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Kaplan (Hasselt University)
DTSTART;VALUE=DATE-TIME:20220623T130000Z
DTEND;VALUE=DATE-TIME:20220623T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/95
DESCRIPTION:Title: Relating properties of homological dimension two algebras\nby Dani
el Kaplan (Hasselt University) as part of FD Seminar\n\n\nAbstract\nLet Q
be a connected\, non-ADE quiver. The preprojective algebra of Q is well-be
haved in the following sense: it is 2-Calabi–Yau\, a noncommutative comp
lete intersection (NCCI)\, and prime. If further Q is extended ADE then th
e preprojective algebra of Q is a noncommutative crepant resolution (NCCR)
over its center\, which is isomorphic to functions on the corresponding d
u Val singularity. In this talk\, I will explain joint work with Travis Sc
hedler which proves these properties for a multiplicative analogue of the
preprojective algebra\, defined by Crawley-Boevey and Shaw\, in the case Q
contains a cycle. Current work in progress aims to prove this for general
Q. The technique involves defining a new notion\, the strong free product
property (SFPP)\, which implies these notions. One then proves the SFPP u
sing multiple applications of Bergman’s Diamond Lemma for ring theory. A
pplications to topology and geometry include computations of certain Cheka
nov–Eliashberg dg-algebras / wrapped Fukaya categories following Etgü
–Lekili\, and a description of the formal local structure of quiver vari
eties.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/95/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Liran Shaul (Charles University)
DTSTART;VALUE=DATE-TIME:20220630T130000Z
DTEND;VALUE=DATE-TIME:20220630T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/96
DESCRIPTION:Title: Finitistic dimensions of differential graded rings\nby Liran Shaul
(Charles University) as part of FD Seminar\n\n\nAbstract\nFinitistic dime
nsions are important homological numerical invariants associated to a ring
. In this talk we explain how to define these invariants over differential
graded rings. We then explain how to extend previous results about finiti
stic dimensions from commutative noetherian rings to commutative noetheria
n differential graded rings. Finally\, we discuss the noncommutative case
and its relation to the finitistic dimension conjecture.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/96/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pierre-Guy Plamondon (Université de Versailles Saint-Quentin)
DTSTART;VALUE=DATE-TIME:20220901T130000Z
DTEND;VALUE=DATE-TIME:20220901T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/97
DESCRIPTION:Title: On some configurations spaces related to algebras of finite representa
tion type\nby Pierre-Guy Plamondon (Université de Versailles Saint-Qu
entin) as part of FD Seminar\n\n\nAbstract\nThe representation theory of a
n algebra gives rise to various\ninteresting geometrical objects\, such as
the g-vector fan and Newton\npolytopes of representations. Classical obje
cts such as the associahedron\ncan be realized in this way\, and these con
structions have interesting\napplications in the categorification of clust
er algebras.\n\nIn this talk\, I will associate to any representation-fini
te algebra\nanother geometrical object\, an affine variety which is closel
y related to\nthe polytopes mentioned above. We will see how this variety
reflects the\ntau-tilting theory of the algebra\, and how F-polynomials of
\nrepresentations give a parametrization of it.\n\nThis is a report on ong
oing work with Nima Arkani-Hamed\, Hadleigh Frost\,\nGiulio Salvatori and
Hugh Thomas.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/97/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cody Gilbert (University of Iowa)
DTSTART;VALUE=DATE-TIME:20220908T130000Z
DTEND;VALUE=DATE-TIME:20220908T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/98
DESCRIPTION:Title: Moduli of Representations of Clannish Algebras\nby Cody Gilbert (U
niversity of Iowa) as part of FD Seminar\n\n\nAbstract\nWe prove irreducib
le components of moduli spaces of semistable representations of clannish a
lgebras are isomorphic to products of projective spaces. This is achieved
by showing irreducible components of varieties of representations of clann
ish algebras can be viewed as irreducible components of skewed-gentle alge
bras\, which we show are always normal. The main theorem generalizes an an
alogous result for moduli of representations of special biserial algebras
proven by Carroll-Chindris-Kinser-Weyman.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/98/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lang Mou (University of Cambridge)
DTSTART;VALUE=DATE-TIME:20220915T130000Z
DTEND;VALUE=DATE-TIME:20220915T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/99
DESCRIPTION:Title: Locally free Caldero-Chapoton functions\nby Lang Mou (University o
f Cambridge) as part of FD Seminar\n\n\nAbstract\nLocally free Caldero-Cha
poton functions are introduced by Geiss-Leclerc-Schröer for locally free
representations of certain quivers with relations associated to skew-symme
trizable matrices. They show that for Dynkin types these functions give fo
rmulas for cluster variables\, generalizing Caldero-Chapoton’s formula i
n simply laced cases. We extend this formula to rank 2 cluster algebras an
d those associated to unpunctured marked bordered surfaces with orbifold p
oints. Part of this talk is based on joint work with Daniel Labardini-Frag
oso.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/99/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raphael Bennett-Tennenhaus (Bielefeld University)
DTSTART;VALUE=DATE-TIME:20221006T130000Z
DTEND;VALUE=DATE-TIME:20221006T140000Z
DTSTAMP;VALUE=DATE-TIME:20220929T074427Z
UID:fd-seminar/100
DESCRIPTION:Title: Semilinear clannish algebras\nby Raphael Bennett-Tennenhaus (Biel
efeld University) as part of FD Seminar\n\n\nAbstract\nString algebras are
monomial algebras introduced by Butler and Ringel\, where they showed any
indecomposable representation is: a string module\, given by a relation-a
voiding walk in the quiver\; or a band module\, given by a cyclic walk and
some module over the Laurent polynomial ring. Clannish algebras\, introdu
ced by Crawley-Boevey\, generalise string algebras - in addition to monomi
al relations\, one specifies a set of special loops\, each bounded by some
monic quadratic polynomial. Butler and Ringel’s classification was then
adapted\, where the class of string (or band) modules splits into asymmet
ric and symmetric subclasses. Said symmetry is a reflection of the walk ab
out a special loop\, and symmetric strings and bands are parameterised by
replacements for the Laurent polynomial ring.\n\nBoth string algebras and
clannish algebras are defined over a field\, and the quadratics bounding s
pecial loops must factor with distinct roots in this field. This talk is b
ased on joint work with Crawley-Boevey (2204.12138)\, where we generalise
the module classification for clannish algebras. We replace the ground fie
ld with a division ring\, we equip each arrow with an automorphism of this
division ring\, and we allow irreducible quadratics to bound the special
loops. The resulting notion of a semilinear clannish algebra specifies to
a generalisation of string algebras considered by Ringel\, where the map a
ssociated to an arrow in any representation must be semilinear with respec
t to its automorphism.\n
LOCATION:https://researchseminars.org/talk/fd-seminar/100/
END:VEVENT
END:VCALENDAR