BEGIN:VCALENDAR
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BEGIN:VEVENT
SUMMARY:Allison Moore (VCU)
DTSTART;VALUE=DATE-TIME:20200417T180000Z
DTEND;VALUE=DATE-TIME:20200417T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/1
DESCRIPTION:Title: Introduction to Khovanov Homology\, part 3\nby Allison Moore (VC
U) as part of VCU Geometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samantha Kirk (NCSU)
DTSTART;VALUE=DATE-TIME:20200424T180000Z
DTEND;VALUE=DATE-TIME:20200424T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/2
DESCRIPTION:Title: Vertex Operator Representations of Twisted Toroidal Lie algebras
\nby Samantha Kirk (NCSU) as part of VCU Geometry and Topology Seminar\n\n
\nAbstract\nA toroidal Lie algebra is the universal central extension of t
he tensor product of a simple finite-dimensional Lie algebra g and the rin
g of Laurent polynomials in 2 or more variables. Given an automorphism of
the Lie algebra g of finite order\, one can construct a "twisted" version
of a toroidal Lie algebra. In this talk\, we will discuss how to construct
vertex operator representations of twisted toroidal Lie algebras.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Katherine Maxwell (University of Minnesota Twin Cities)
DTSTART;VALUE=DATE-TIME:20200501T180000Z
DTEND;VALUE=DATE-TIME:20200501T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/3
DESCRIPTION:Title: The super Mumford form and Sato grassmannian\nby Katherine Maxwe
ll (University of Minnesota Twin Cities) as part of VCU Geometry and Topol
ogy Seminar\n\n\nAbstract\nThe moduli space of curves and representations
of the Virasoro algebra each separately give rise to the number $6j^2-6j+1
$. In the 1980s\, this observation was shown not to be a mere coincidence
by involving the infinite-dimensional Sato grassmannian. In this talk\, we
will first discuss this construction of Kontsevich and Arbarello\, De Con
cini\, Kac\, and Procesi\, and then discuss a supersymmetric generalizatio
n. Our main result is the existence of a flat holomorphic connection on th
e line bundle $\\lambda_{3/2}\\otimes\\lambda^{-5}_{1/2}$ on the moduli sp
ace of triples: a super Riemann surface\, a Neveu-Schwarz puncture\, and a
formal coordinate system.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Sussan (CUNY)
DTSTART;VALUE=DATE-TIME:20200508T180000Z
DTEND;VALUE=DATE-TIME:20200508T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/4
DESCRIPTION:Title: p-DG structures and categorification\nby Joshua Sussan (CUNY) as
part of VCU Geometry and Topology Seminar\n\n\nAbstract\nThe Jones polyno
mial is an invariant of links coming from the representation theory of qua
ntum groups. After reviewing its construction\, we will discuss the goals
of the categorification program and how the notion of a p-DG algebra natu
rally arises when looking to categorify the WRT 3-manifold invariant.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scott Taylor (Colby College)
DTSTART;VALUE=DATE-TIME:20200515T180000Z
DTEND;VALUE=DATE-TIME:20200515T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/5
DESCRIPTION:Title: Lower bounds on the tunnel number of composite spatial theta graphs<
/a>\nby Scott Taylor (Colby College) as part of VCU Geometry and Topology
Seminar\n\n\nAbstract\nThe tunnel number of a graph embedded in a 3-dimens
ional manifold is the fewest number of arcs needed so that the union of th
e graph with the arcs has handlebody exterior. The behavior of tunnel numb
er with respect to connected sum of knots can vary dramatically\, dependin
g on the knots involved. However\, a classical theorem of Scharlemann and
Schultens says that the tunnel number of a composite knot is at least the
number of factors. For theta graphs\, trivalent vertex sum is the operatio
n which most closely resembles the connected sum of knots. The analogous t
heorem of Scharlemann and Schultens no longer holds\, however. I will prov
ide a sharp lower bound for the tunnel number of composite theta graphs\,
using recent work on a new knot invariant which is additive under connecte
d sum and trivalent vertex sum. This is joint work with Maggy Tomova.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Han-Bom Moon (Fordham University)
DTSTART;VALUE=DATE-TIME:20200522T180000Z
DTEND;VALUE=DATE-TIME:20200522T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/6
DESCRIPTION:Title: Finite generation of the algebra of conformal blocks via birational
geometry.\nby Han-Bom Moon (Fordham University) as part of VCU Geometr
y and Topology Seminar\n\n\nAbstract\nA Conformal block is a representatio
n-theoretic object constructed as an example of two-dimensional conformal
field theory (WZW model). For each simple Lie algebra $\\mathfrak{g}$ and
a stable curve\, the set of conformal blocks naturally has an algebra stru
cture. We prove\, by employing birational geometric techniques\, the finit
e generation of the algebra of conformal blocks for $\\mathfrak{g} = \\mat
hfrak{sl}_r$. This is joint work with Sang-Bum Yoo.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Florencia Orosz Hunziker (Harvard University)
DTSTART;VALUE=DATE-TIME:20200529T180000Z
DTEND;VALUE=DATE-TIME:20200529T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/7
DESCRIPTION:Title: Tensor categories arising from the Virasoro algebra\nby Florenci
a Orosz Hunziker (Harvard University) as part of VCU Geometry and Topology
Seminar\n\n\nAbstract\nIn this talk we will discuss the tensor structure
associated to certain representations of the Virasoro algebra. In particul
ar\, we will show that there is a braided tensor category structure on the
category of C1-cofinite modules for the Virasoro vertex operator algebras
of arbitrary central charge.\nThis talk is based on joint work with Jinwe
i Yang\, Thomas Creutzig\, Cuibo Jiang and David Ridout.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matt Szczesny (Boston University)
DTSTART;VALUE=DATE-TIME:20200605T180000Z
DTEND;VALUE=DATE-TIME:20200605T190000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/8
DESCRIPTION:Title: Toric Hall Algebras\nby Matt Szczesny (Boston University) as par
t of VCU Geometry and Topology Seminar\n\n\nAbstract\nI will describe a co
nstruction that attaches to a smooth projective toric variety a co-commuta
tive Hopf algebra (in fact\, an enveloping algebra). It arises as a Hall a
lgebra of special coherent sheaves on the associated monoid scheme\, using
a version of algebraic geometry over $\\mathbb{F}_1$. These sheaves are c
ombinatorial in nature\, and look locally like (possibly infinite) n-dimen
sional skew shapes. I will discuss some evidence to suggest that these Hal
l algebras are classical limits of quantum groups\, and in some cases rela
te them to known loop algebras. This is joint work with Jaiung Jun.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Olof Bergvall (University of Gävle)
DTSTART;VALUE=DATE-TIME:20200911T190000Z
DTEND;VALUE=DATE-TIME:20200911T200000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/9
DESCRIPTION:Title: Configurations\, arrangements and moduli spaces\nby Olof Bergval
l (University of Gävle) as part of VCU Geometry and Topology Seminar\n\n\
nAbstract\nIn this talk we will encounter certain configuration spaces of
points in the projective plane and see how they relate to certain moduli s
paces of curves and surfaces (marked with e.g. level structures\, geometri
c markings and anticanonical curves). We will also see how to compute thei
r cohomology\, equivariantly with respect to certain natural group actions
\, by using techniques from the theory of subspace arrangements.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Wang (Harvard)
DTSTART;VALUE=DATE-TIME:20201009T190000Z
DTEND;VALUE=DATE-TIME:20201009T200000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/10
DESCRIPTION:Title: Floer and Khovanov homologies of band sums\nby Joshua Wang (Har
vard) as part of VCU Geometry and Topology Seminar\n\n\nAbstract\nGiven a
nontrivial band sum of two knots\, we may add full twists to the band to o
btain a family of knots indexed by the integers. In this talk\, I'll show
that the knots in this family have the same Heegaard and instanton knot Fl
oer homology but distinct Khovanov homology\, generalizing a result of M.
Hedden and L. Watson. A key component of the argument is a proof that each
of the three knot homologies detects the trivial band. The main applicati
on is a verification of the generalized cosmetic crossing conjecture for s
plit links.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adam Sikora (SUNY Buffalo)
DTSTART;VALUE=DATE-TIME:20201023T190000Z
DTEND;VALUE=DATE-TIME:20201023T200000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/11
DESCRIPTION:Title: Tangle Equations\, the Jones conjecture and quantum rational number
s\nby Adam Sikora (SUNY Buffalo) as part of VCU Geometry and Topology
Seminar\n\n\nAbstract\nWe study systems of 2-tangle equations\, which play
an important role in the analysis of enzyme actions on DNA strands. We sh
ow the benefits of considering such systems in the context of framed tangl
es and\, in particular\, we conjecture uniqueness of solutions in that cas
e. We prove a version of this conjecture for rational tangles and we relat
e this conjecture to the Jones Unknotting conjecture\, which potentially o
pens a door to a purely topological line of attack on the Jones conjecture
. Additionally\, we relate systems of tangle equations to the Cosmetic Sur
gery Conjecture.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joshua Lackman (Toronto)
DTSTART;VALUE=DATE-TIME:20201106T200000Z
DTEND;VALUE=DATE-TIME:20201106T210000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/12
DESCRIPTION:Title: Quantization of (Holomorphic) Poisson Manifolds\nby Joshua Lack
man (Toronto) as part of VCU Geometry and Topology Seminar\n\n\nAbstract\n
We will discuss how\, starting with a Poisson manifold\, one may produce a
quantization via its symplectic groupoid\, and hopefully a noncommutative
algebra.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Iulia Gheorghita (Boston College)
DTSTART;VALUE=DATE-TIME:20201120T200000Z
DTEND;VALUE=DATE-TIME:20201120T210000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/13
DESCRIPTION:Title: Effective classes in the projectivized k-th Hodge bundle\nby Iu
lia Gheorghita (Boston College) as part of VCU Geometry and Topology Semin
ar\n\n\nAbstract\nThe k-th Hodge bundle over the moduli space of curves pa
rametrizes stable k-differentials. In this talk\, we will discuss several
effective classes in both the projectivized k-th Hodge bundle and the proj
ectivized n-marked k-th Hodge bundle. In the n-marked k-th Hodge bundle we
will show how to compute the locus where the k-differential has zeros at
the n marked points for the cases n=1\, 2\, as well as for the case n <= k
. We will then show how to use these classes to compute the classes of eff
ective divisors in the unmarked projectivized k-th Hodge bundle where the
zeros of the k-differentials satisfy a Brill-Noether condition.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Jose Villarreal
DTSTART;VALUE=DATE-TIME:20201211T160000Z
DTEND;VALUE=DATE-TIME:20201211T170000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/14
DESCRIPTION:Title: Logarithmic vertex algebras\nby Juan Jose Villarreal as part of
VCU Geometry and Topology Seminar\n\n\nAbstract\nIn this talk\, we will i
ntroduce the notion of logarithmic vertex algebra\, which is a vertex alge
bra with logarithmic singularities in the operator product expansion of qu
antum fields\; thus providing a rigorous formulation of the algebraic prop
erties of quantum fields in logarithmic conformal field theory. We develop
a framework that allows many results about vertex algebras to be transfer
red to logarithmic vertex algebras\, and we describe some examples. This i
s a joint work with Bojko Bakalov.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gage Martin (Boston College)
DTSTART;VALUE=DATE-TIME:20201113T200000Z
DTEND;VALUE=DATE-TIME:20201113T210000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/16
DESCRIPTION:Title: Khovanov homology\, knot Floer homology\, and link detection\nb
y Gage Martin (Boston College) as part of VCU Geometry and Topology Semina
r\n\n\nAbstract\nKhovanov homology and knot/link Floer homology are invari
ants of links in S^3 categorifying the more classical Jones and Alexander
polynomials respectively. There are many formal similarities between the t
heories but some key differences as well. The relationships between Khovan
ov homology and knot/link Floer homology has been a source of inspiration
in each theory. In this talk\, we will give an overview of both theories
in the context of link detection\, mention some of techniques used in prov
ing detection results in each of the theories\, and sketch proofs that Kho
vanov homology detects the torus link T(2\,6) and link Floer homology dete
cts the torus links T(2\,2n). This is partially joint work with Fraser Bin
ns.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicola Pagani (University of Liverpool)
DTSTART;VALUE=DATE-TIME:20210205T200000Z
DTEND;VALUE=DATE-TIME:20210205T210000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/17
DESCRIPTION:Title: Geometry of genus 1 fine compactified Jacobians\nby Nicola Pag
ani (University of Liverpool) as part of VCU Geometry and Topology Seminar
\n\n\nAbstract\nA classical construction in algebraic geometry associates
with every nonsingular complex projective curve its Jacobian\, a complex p
rojective variety of dimension equal to the genus of the curve. A similar
construction is available for singular curves\, but the resulting Jacobian
variety fails in general to be compact. In this talk we introduce a gener
al abstract notion of fine compactified Jacobian for nodal curves of arbit
rary genus.\n\nWe focus on genus 1 and discuss combinatorial classificatio
n results for fine compactified Jacobians in the case of a single stable c
urve\, and in the case of the universal family over the moduli space of st
able pointed curves. In the former case\, our abstract notion finds back
objects that had already been constructed by Oda-Seshadri and others. In t
he latter case our complete classification exhibits new examples. If time
permits it\, we will discuss how to calculate the cohomology of these comp
actified Jacobians. \n\nA joint work with Orsola Tommasi.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bin Gui (Rutgers University)
DTSTART;VALUE=DATE-TIME:20210305T200000Z
DTEND;VALUE=DATE-TIME:20210305T210000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/18
DESCRIPTION:Title: Conjugation and positivity of conformal blocks\nby Bin Gui (Rut
gers University) as part of VCU Geometry and Topology Seminar\n\n\nAbstrac
t\nGiven a strongly rational unitary VOA V\, a Hermitian form on the space
of its intertwining operators was introduced recently to understand the u
nitarity of the representation modular tensor category Rep(V). It was actu
ally shown that\, along with some natural assumptions\, if this Hermitian
form (which is necessarily non-degenerate) is positive\, namely\, if it is
an inner product\, then Rep(V) is unitary. The crucial step of this story
is to prove the positivity of the Hermitian form. In this talk\, I give a
geometric interpretation of this positivity problem using (self)conjugate
Riemann surfaces and (self)conjugate conformal blocks.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oğuz Şavk (Boğaziçi University)
DTSTART;VALUE=DATE-TIME:20210319T190000Z
DTEND;VALUE=DATE-TIME:20210319T200000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/19
DESCRIPTION:Title: Classical and New Plumbings Bounding Contractible Manifolds and Rat
ional Homology Balls\nby Oğuz Şavk (Boğaziçi University) as part o
f VCU Geometry and Topology Seminar\n\n\nAbstract\nA classical question in
low-dimensional topology asks which homology 3-spheres bound contractible
4-manifolds. In this talk\, we address this question for plumbed 3-manifo
lds and we present two new infinite families. Along the way\, we also simp
ly reprove most of the classical works of Akbulut and Kirby\, Fukuhara\, F
ickle\, Maruyama\, Martin\, Casson and Harer\, and Stern around the ninete
en-eighties. Therefore\, our approach provides a unification of classical
and new results via a modification of Mazur’s famous argument. One can w
eaken the above question and ask which homology 3-spheres bound rational h
omology 4-balls. Surprisingly\, this question still remains hard. Recently
\, significant progress occurred due to Akbulut and Larson. Using their te
chnique\, we exhibit new homology 3-spheres bounding rational homology 4-b
alls but not integral homology 4-balls. These 3-manifolds represent non-tr
ivial elements in the kernel of the natural map from the homology cobordis
m group to the rational homology cobordism group.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan C. Johnson (University of Texas at Austin)
DTSTART;VALUE=DATE-TIME:20210402T190000Z
DTEND;VALUE=DATE-TIME:20210402T200000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/20
DESCRIPTION:Title: Bi-Orderability Techniques and Double Twist Links\nby Jonathan
C. Johnson (University of Texas at Austin) as part of VCU Geometry and Top
ology Seminar\n\n\nAbstract\nThe bi-orderability of link groups has become
a fascinating research topic. In this talk\, we will survey some useful t
ools that have been developed to investigate the bi-orderabily of link com
plements\, including results of Linnell-Rhemtulla-Rolfsen\, Ito\, and Kin-
Rolfsen. In particular\, we will apply these techniques to the double twis
t link groups.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hannah Turner (University of Texas at Austin)
DTSTART;VALUE=DATE-TIME:20210212T200000Z
DTEND;VALUE=DATE-TIME:20210212T210000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/21
DESCRIPTION:Title: Branched cyclic covers and L-spaces\nby Hannah Turner (Universi
ty of Texas at Austin) as part of VCU Geometry and Topology Seminar\n\nAbs
tract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Allison Moore (Virginia Commonwealth University)
DTSTART;VALUE=DATE-TIME:20210430T190000Z
DTEND;VALUE=DATE-TIME:20210430T200000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/22
DESCRIPTION:by Allison Moore (Virginia Commonwealth University) as part of
VCU Geometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vance Blankers (Northeastern University)
DTSTART;VALUE=DATE-TIME:20210917T140000Z
DTEND;VALUE=DATE-TIME:20210917T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/23
DESCRIPTION:Title: Alternative compactifications of the moduli space of curves\nby
Vance Blankers (Northeastern University) as part of VCU Geometry and Topo
logy Seminar\n\n\nAbstract\nThe moduli space of curves is an important obj
ect in modern algebraic geometry\, both interesting in its own right and s
erving as a test space for broader geometric programs. These often require
the space to be compact\, which leads to a variety of choices for compact
ification\, the most well-known of which is the Deligne-Mumford-Knudsen co
mpactification by stable curves\, originally introduced in 1969. Since the
n\, several alternative compactifications have been constructed and studie
d\, and in 2013 David Smyth used a combinatorial framework to make progres
s towards classifying all "sufficiently nice" compactifications. In this t
alk\, I'll discuss some of the most well-studied compactifications\, as we
ll as two new compactifications\, which together classify the Gorenstein c
ompactifications in genus 0 and genus 1.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:César Lozano Huerta (Universidad Nacional Autónoma de México -
Oaxaca)
DTSTART;VALUE=DATE-TIME:20210924T140000Z
DTEND;VALUE=DATE-TIME:20210924T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/24
DESCRIPTION:Title: On the Weak Lefschetz Principle in birational geometry\nby Cés
ar Lozano Huerta (Universidad Nacional Autónoma de México - Oaxaca) as p
art of VCU Geometry and Topology Seminar\n\n\nAbstract\nIn this talk we wi
ll discuss the weak Lefschetz Principle in the context of birational geome
try.\n\nOur departing point will be the influential work of Solomon Lefsch
etz started in 1924. We will look at the original formulation of the Lefsc
hetz hyperplane theorem in algebraic topology and build up to recent devel
opments of it in birational geometry. In doing so\, the slogan of the talk
will be the following: there are many scenarios in geometry in which anal
ogous versions of the Lefschetz hyperplane theorem hold. Such scenarios ar
e somewhat unexpected and have had a profound impact in mathematics.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mara Ungureanu (Albert-Ludwigs-Universität Freiburg)
DTSTART;VALUE=DATE-TIME:20211008T140000Z
DTEND;VALUE=DATE-TIME:20211008T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/25
DESCRIPTION:Title: Counts of secant planes to varieties and universal polynomials\
nby Mara Ungureanu (Albert-Ludwigs-Universität Freiburg) as part of VCU G
eometry and Topology Seminar\n\n\nAbstract\nFor a curve in projective spac
e\, the count of varieties parametrising its secant planes is among the mo
st studied problems in classical enumerative geometry. We shall start wit
h a gentle introduction to secant varieties and then explore the connectio
n between their enumerative geometry and Virasoro algebras on one side\, a
nd tautological integrals on the other.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scott Mullane (Humboldt Universität zu Berlin)
DTSTART;VALUE=DATE-TIME:20211119T150000Z
DTEND;VALUE=DATE-TIME:20211119T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/26
DESCRIPTION:Title: The birational geometry of the moduli space of pointed hyperellipti
c curves\nby Scott Mullane (Humboldt Universität zu Berlin) as part o
f VCU Geometry and Topology Seminar\n\n\nAbstract\nThe moduli space of poi
nted hyperelliptic curves is a seemingly simple object with perhaps unexpe
ctedly interesting geometry. I will report on joint work with Ignacio Barr
os towards a full classification of both the Kodaira dimension and the str
ucture of the effective cone of these moduli spaces.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Margherita Lelli-Chiesa (Università Roma 3)
DTSTART;VALUE=DATE-TIME:20211015T140000Z
DTEND;VALUE=DATE-TIME:20211015T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/27
DESCRIPTION:Title: Brill-Noether theory of curves on abelian surfaces\nby Margheri
ta Lelli-Chiesa (Università Roma 3) as part of VCU Geometry and Topology
Seminar\n\n\nAbstract\nBrill-Noether theory investigates the ways in which
an algebraic curve can be embedded in some projective space. I will recal
l the most relevant results in the theory and their relation with curves l
ying on K3 surfaces. I will then illustrate more recent results on the Bri
ll-Noether theory of curves on Abelian surfaces highlightening the major d
ifferences with respect to K3 surfaces and some applications to the moduli
space of curves.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seppo Niemi-Colvin (Duke University)
DTSTART;VALUE=DATE-TIME:20210910T140000Z
DTEND;VALUE=DATE-TIME:20210910T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/28
DESCRIPTION:Title: Invariance of Knot Lattice Homology\nby Seppo Niemi-Colvin (Duk
e University) as part of VCU Geometry and Topology Seminar\n\n\nAbstract\n
Links of singularity and generalized algebraic links are ways of construct
ing three-manifolds and smooth links inside them from algebraic surfaces a
nd curves inside them. Némethi created lattice homology as an invariant f
or links of normal surface singularities which developed out of computatio
ns for Heegaard Floer homology. Later Ozsváth\, Stipsicz\, and Szabó def
ined knot lattice homology for generalized algebraic knots in rational hom
ology spheres\, which is known to play a similar role to knot Floer homolo
gy and is known to compute knot Floer in some cases. I discuss a proof tha
t knot lattice is an invariant of the smooth knot type\, which had been pr
eviously suspected but not confirmed.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jingling Yang (The Chinese University of Hong Kong\, Shenzhen)
DTSTART;VALUE=DATE-TIME:20211029T140000Z
DTEND;VALUE=DATE-TIME:20211029T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/29
DESCRIPTION:Title: Distance one surgeries on the lens space L(n\,1) and band surgeries
on the torus knot T(2\,n)\nby Jingling Yang (The Chinese University o
f Hong Kong\, Shenzhen) as part of VCU Geometry and Topology Seminar\n\n\n
Abstract\nIt has been well known that any closed\, orientable 3-manifold c
an be obtained by performing Dehn surgery on a link in $S^3$. One of the m
ost prominent problems in 3-manifold topology is to list all the possible
lens spaces that can be obtained by a Dehn surgery along a knot in $S^3$\,
which has been solved by Greene. A natural generalization of this problem
is to list all the possible lens spaces that can be obtained by a Dehn su
rgery from other lens spaces. Besides\, considering surgeries between lens
spaces is also motivated from DNA topology. In this talk\, we will discus
s distance one surgeries between lens spaces $L(n\, 1)$ with $n \\geq 5$ o
dd and lens spaces $L(s\,1)$ for $s \\neq 0 \\in \\mathbb{Z}$ and correspo
nding band surgeries from $T(2\, n)$ to $T(2\, s)$\, by using Heegaard Flo
er mapping cone formula. We give an almost complete classification of the
above surgeries.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Vitagliano (Universita' di Salerno)
DTSTART;VALUE=DATE-TIME:20211105T140000Z
DTEND;VALUE=DATE-TIME:20211105T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/30
DESCRIPTION:Title: Homogeneous G-structures\nby Luca Vitagliano (Universita' di Sa
lerno) as part of VCU Geometry and Topology Seminar\n\n\nAbstract\nG-struc
tures unify several interesting geometries including: almost complex\, Rie
mannian\, almost symplectic geometry\, etc.\, the integrable versions of w
hich being complex\, flat Riemannian\, symplectic geometry\, etc. Contact
manifolds are odd dimensional analogues of symplectic manifolds but\, desp
ite this\, there is no natural way to understand them as manifolds with an
ordinary integrable G-structure. In this talk\, we present a possible sol
ution to this discrepancy. Our proposal is based on a new notion of homog
eneous G-structures. Interestingly\, besides contact\, the latter include
other nice (old and new) geometries including: cosymplectic\, almost conta
ct\, and a curious “homogeneous version” of Riemannian geometry. This
is joint work with A. G. Tortorella and O. Yudilevich.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert DeYeso (North Carolina State University)
DTSTART;VALUE=DATE-TIME:20211001T140000Z
DTEND;VALUE=DATE-TIME:20211001T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/31
DESCRIPTION:Title: (Heegaard Floer) thin knots satisfy the Cabling Conjecture\nby
Robert DeYeso (North Carolina State University) as part of VCU Geometry an
d Topology Seminar\n\n\nAbstract\nThe Cabling Conjecture of González-Acu
ña and Short holds that only cable knots admit a reducible surgery\, whic
h is Dehn surgery containing an essential 2-sphere. For surgeries along (H
eegaard Floer) thin knots\, we approach this conjecture by comparing the r
elative Maslov gradings and periodicity structure of their Floer homology.
This is primarily done by reinterpreting these objects via immersed curve
s techniques that recover Floer homology\, inspired by Hanselman's approac
h to the Cosmetic Surgery Conjecture.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Villareal
DTSTART;VALUE=DATE-TIME:20211210T150000Z
DTEND;VALUE=DATE-TIME:20211210T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/32
DESCRIPTION:Title: Logarithmic vertex algebras\nby Juan Villareal as part of VCU G
eometry and Topology Seminar\n\n\nAbstract\nIn this talk\, I want to expla
in a generalization of vertex algebras called logarithmic vertex algebras.
In this work\, we develop a framework that allows many results about vert
ex algebras to be extended to logarithmic vertex algebras. In particular\,
I will mention one example which is motivated by physics\, this example
exhibits some unexpected new features that are peculiar to the logarithmic
case. Finally\, I will mention a relation between logarithmic vertex alge
bras and non-local poisson vertex algebras. This is joint work with Bojko
Bakalov.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eric Samperton (University of Illinois at Urbana-Champaign)
DTSTART;VALUE=DATE-TIME:20220128T150000Z
DTEND;VALUE=DATE-TIME:20220128T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/33
DESCRIPTION:Title: Topological quantum computation is hyperbolic\nby Eric Samperto
n (University of Illinois at Urbana-Champaign) as part of VCU Geometry and
Topology Seminar\n\n\nAbstract\nWe show that a topological quantum comput
er based on the evaluation of a Witten-Reshetikhin-Turaev TQFT invariant o
f knots can always be arranged so that the knot diagrams one compiles are
hyperbolic. Furthermore\, the diagrams can be arranged to have additional
nice properties\, such as being alternating with minimal crossing number.
Various complexity-theoretic hardness results regarding the calculation of
quantum invariants of knots follow as corollaries. In particular\, we arg
ue that the hyperbolic geometry of knots is unlikely to be useful for topo
logical quantum computation.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Balazs Elek (Virginia Commonwealth University)
DTSTART;VALUE=DATE-TIME:20220204T180000Z
DTEND;VALUE=DATE-TIME:20220204T185000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/34
DESCRIPTION:Title: Heaps\, Crystals and Preprojective Algebra Modules\nby Balazs E
lek (Virginia Commonwealth University) as part of VCU Geometry and Topolog
y Seminar\n\n\nAbstract\nKashiwara crystals are combinatorial gadgets asso
ciated to a representation of a reductive algebraic group that enable us t
o understand the structure of the representation in purely combinatorial t
erms. We will describe a type-independent combinatorial construction of cr
ystals of the form $B(n\\lambda)$\, where $\\lambda$ is a dominant minuscu
le weight\, using the heap associated to a fully commutative element in th
e Weyl group. Then we will discuss how we can use the heap to also define
a module for the preprojective algebra of the underlying Dynkin quiver. Us
ing the work of Savage and Tingley\, we also realize the crystal $B(n\\lam
bda)$ via irreducible components of the quiver Grassmannians of $n$ copies
of this module\, and we describe an explicit crystal isomorphism between
the two models. This is joint work with Anne Dranowski\, Joel Kamnitzer an
d Calder Morton-Ferguson.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francesco Sala (Università di Pisa)
DTSTART;VALUE=DATE-TIME:20220218T150000Z
DTEND;VALUE=DATE-TIME:20220218T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/35
DESCRIPTION:Title: Two-dimensional cohomological Hall algebras\nby Francesco Sala
(Università di Pisa) as part of VCU Geometry and Topology Seminar\n\n\nAb
stract\nThe present talk aims at introducing the theory of 2-dimensional c
ohomological Hall algebras and their relations with moduli spaces in algeb
raic geometry and representation theory. In the second part of the talk\,
I will focus on those associated to curves and surfaces and discuss their
categorification. If time permits\, I will describe in detail the cohomolo
gical Hall algebra of a Kleinian surface singularity.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Swarnava Mukhopadhyay (Tata Institute of Fundamental Research)
DTSTART;VALUE=DATE-TIME:20220211T150000Z
DTEND;VALUE=DATE-TIME:20220211T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/36
DESCRIPTION:Title: Graph potentials and their periods\nby Swarnava Mukhopadhyay (T
ata Institute of Fundamental Research) as part of VCU Geometry and Topolog
y Seminar\n\n\nAbstract\nWe introduce graph potentials\, which are Laurent
polynomials associated to\n(colored) trivalent graphs. These graph potent
ials encode degenerations of the \nmoduli space of rank two bundles with f
ixed determinant. \n\nIn this talk\, we will discuss how the graph potenti
al defines a topological quantum field\ntheory. Applying the TQFT machiner
y gives us an efficient way to compute periods of these potentials. \nIf t
ime permits\, we will explain how these are related to the moduli spaces
of rank two bundles from \nthe perspective of mirror symmetry. This is a
joint work with Pieter Belmans and Sergey Galkin.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniele Agostini (Max-Planck-Institut für Mathematik in den Natur
wissenschaften in Leipzig)
DTSTART;VALUE=DATE-TIME:20220304T150000Z
DTEND;VALUE=DATE-TIME:20220304T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/37
DESCRIPTION:by Daniele Agostini (Max-Planck-Institut für Mathematik in de
n Naturwissenschaften in Leipzig) as part of VCU Geometry and Topology Sem
inar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniele Agostini (Max-Planck-Institut für Mathematik in den Natur
wissenschaften in Leipzig)
DTSTART;VALUE=DATE-TIME:20220318T140000Z
DTEND;VALUE=DATE-TIME:20220318T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/38
DESCRIPTION:Title: Singular curves\, degenerate theta functions and KP solutions\n
by Daniele Agostini (Max-Planck-Institut für Mathematik in den Naturwisse
nschaften in Leipzig) as part of VCU Geometry and Topology Seminar\n\n\nAb
stract\nThe KP equation is a PDE that describes waves in shallow water. Qu
ite surprisingly\, smooth algebraic curves give rise to solutions to the K
P equation via Riemann's theta function. Singular curves produce solutions
as well\, but the theta function in this case becomes degenerate. I will
present some results in this direction\, focusing on soliton and rational
solutions.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alejandro Cabrera (Universidade Federal do Rio de Janeiro\, Brasil
)
DTSTART;VALUE=DATE-TIME:20220325T140000Z
DTEND;VALUE=DATE-TIME:20220325T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/39
DESCRIPTION:Title: Infinite dimensional Dirac structures and moduli spaces\nby Ale
jandro Cabrera (Universidade Federal do Rio de Janeiro\, Brasil) as part o
f VCU Geometry and Topology Seminar\n\n\nAbstract\nIn this talk\, we first
recall a class of geometric structures called Courant algebroids and Dira
c structures. We then proceed to outline their study on infinite dimension
al manifolds and stress their advantage with respect to more traditional g
eometries (notably\, Poisson) in the infinite dimensional context. We then
study their reduction and apply this setting to the description of geomet
ric structures on moduli spaces of principal connections. This is joint wo
rk with M. Gualtieri and E. Meinrenken. Along the way\, we recover several
known results involving moduli on surfaces and comment on possible novel
applications\, including Topological Field Theories.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Konstantinos Varvarezos (Princeton University)
DTSTART;VALUE=DATE-TIME:20220401T140000Z
DTEND;VALUE=DATE-TIME:20220401T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/40
DESCRIPTION:Title: Heegaard Floer homology\, immersed curves\, and chirally cosmetic s
urgeries\nby Konstantinos Varvarezos (Princeton University) as part of
VCU Geometry and Topology Seminar\n\n\nAbstract\nDehn surgery is a common
method for obtaining 3-manifolds from knots. A pair of (Dehn) surgeries o
n a knot is called chirally cosmetic if the resulting manifolds are homeom
orphic with opposite orientations. Making use of immersed curve formulatio
ns of Heegaard Floer invariants\, we discuss new obstructions to the exist
ence of such surgeries\, which we apply to certain families of knots. In p
articular\, it turns out that combined with previously known results\, the
se obstructions are sufficient to completely classify chirally cosmetic su
rgeries on odd alternating pretzel knots. Furthermore\, we are able to rul
e out cosmetic surgeries for L-space knots along slopes with opposite sign
s.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex McCleary (Ohio State University)
DTSTART;VALUE=DATE-TIME:20220429T140000Z
DTEND;VALUE=DATE-TIME:20220429T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/42
DESCRIPTION:Title: An Introduction to Multiparameter Persistent Homology\nby Alex
McCleary (Ohio State University) as part of VCU Geometry and Topology Semi
nar\n\n\nAbstract\nPersistent homology is a method for studying topologica
l features of data sets. Originally developed in the early 2000s\, it has
proven useful for a wide range of applications including neuroscience\, me
dical research\, chemistry\, weather prediction\, and financial modelling.
We will start with a brief introduction to persistent homology and multip
arameter persistent homology followed by some recent results on multiparam
eter persistence.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marco Aldi (VCU)
DTSTART;VALUE=DATE-TIME:20220422T140000Z
DTEND;VALUE=DATE-TIME:20220422T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/43
DESCRIPTION:Title: Generalized Polynomial Structures\nby Marco Aldi (VCU) as part
of VCU Geometry and Topology Seminar\n\n\nAbstract\nThe generalized tangen
t bundle is a geometric object that appears naturally in both physics and
mathematics. Generalized almost complex structures\, encompassing classica
l almost complex structure and almost symplectic structures\, are an endom
orphisms of the generalized tangent that square to negative the identity.
In this talk we discuss more general endomorphims satisfying an arbitrary
polynomial equation with constant coefficients. As it turns out\, particul
ar care is required in properly formulating the correct integrability cond
itions. This is joint work with Daniele Grandini.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Bud (Humboldt University in Berlin)
DTSTART;VALUE=DATE-TIME:20220902T150000Z
DTEND;VALUE=DATE-TIME:20220902T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/44
DESCRIPTION:Title: Moduli of Prym curves and Prym-Brill-Noether theory\nby Andrei
Bud (Humboldt University in Berlin) as part of VCU Geometry and Topology S
eminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sergio Da Silva (Virginia State University)
DTSTART;VALUE=DATE-TIME:20220923T150000Z
DTEND;VALUE=DATE-TIME:20220923T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/45
DESCRIPTION:Title: An Introduction to Geometric Vertex Decomposability\nby Sergio
Da Silva (Virginia State University) as part of VCU Geometry and Topology
Seminar\n\nLecture held in Room 4145 Harris Hall.\n\nAbstract\nA Gröbner
degeneration is a useful method to reduce problems involving ideals to the
monomial ideal setting. In the square-free case\, we can associate a simp
licial complex to a monomial ideal and ask whether this complex is vertex
decomposable. Another tool in this direction\, called a geometric vertex d
ecomposition\, is a generalization of this technique first introduced by K
nutson-Miller-Yong to study diagonal degenerations of Schubert varieties.
Later uses of the concept mostly occurred in the context of Schubert geome
try\, until recent work of Klein-Rajchgot established a connection to liai
son theory. The interplay between these two theories can be used to analyz
e degenerations\, construct Gröbner bases\, and find families of ideals w
hich are glicci (in the Gorenstein liaison class of a complete intersectio
n). In this talk\, I will introduce geometric vertex decomposability and h
ighlight its applications to toric ideals of graphs and Hessenberg varieti
es.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:TBA
DTSTART;VALUE=DATE-TIME:20221028T150000Z
DTEND;VALUE=DATE-TIME:20221028T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/46
DESCRIPTION:by TBA as part of VCU Geometry and Topology Seminar\n\nAbstrac
t: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Marcelo Servan (University of Chicago)
DTSTART;VALUE=DATE-TIME:20220930T150000Z
DTEND;VALUE=DATE-TIME:20220930T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/47
DESCRIPTION:Title: On the uniqueness of the Prym map\nby Carlos Marcelo Servan (Un
iversity of Chicago) as part of VCU Geometry and Topology Seminar\n\n\nAbs
tract\nThe Prym map associates to a double unbranched cover $p:Y \\to X$ o
f a smooth complex curve of X of genus g\, a principally polarized abelian
variety (ppav) Prym(p). Denote by $R_g$ to the moduli space of such doubl
e covers and by $A_h$ the moduli space of ppavs of dimension h. We will sh
ow that for $g \\geq 4$ and $h \\leq g-1$\, Prym is the unique non-constan
t map of complex orbifolds between $R_g \\to A_h$. A key step in the proof
is a classification of homomorphisms at the level of orbifold fundamental
groups\, which uses arguments from low-dimensional topology and geometric
group theory.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samantha Allen (Duquesne University)
DTSTART;VALUE=DATE-TIME:20221007T150000Z
DTEND;VALUE=DATE-TIME:20221007T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/48
DESCRIPTION:Title: Unknotting via null-homologous twists and multi-twists\nby Sama
ntha Allen (Duquesne University) as part of VCU Geometry and Topology Semi
nar\n\n\nAbstract\nThe untwisting number of a knot K is the minimum number
of null-homologous full twists required to unknot K. The surgery descript
ion number of K can be defined similarly\, allowing for multiple full twis
ts in a single twisting region. We can find no examples of knots in the li
terature where these two invariants are not equal. In this talk\, I will p
rovide the first known examples where untwisting number and surgery descri
ption number are not equal and discuss challenges to distinguishing these
invariants in general. While these invariants are defined geometrically\,
our methods will involve several “algebraic” versions of unknotting op
erations. In addition\, we show the surprising result that the untwisting
number of a knot is at most three times its surgery description number. Th
is work is joint with Kenan Ince\, Seungwon Kim\, Benjamin Ruppik\, and Ha
nnah Turner.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pengyu Liu (UC Davis)
DTSTART;VALUE=DATE-TIME:20221209T160000Z
DTEND;VALUE=DATE-TIME:20221209T165000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/49
DESCRIPTION:Title: A graph polynomial that distinguishes tree topologies and its appli
cations\nby Pengyu Liu (UC Davis) as part of VCU Geometry and Topology
Seminar\n\n\nAbstract\nIn this talk\, I will define a graph polynomial fo
r trees and show that the polynomial is a complete invariant for unlabeled
trees. Then\, we introduce distance-based methods for analyzing tree stru
ctures with the polynomial\, and we demonstrate its applications in molecu
lar evolutionary and structural biology.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fernando Etayo Gordejuela (Universidad de Cantabria)
DTSTART;VALUE=DATE-TIME:20220916T170000Z
DTEND;VALUE=DATE-TIME:20220916T175000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/50
DESCRIPTION:Title: Structures on Generalized Geometry\nby Fernando Etayo Gordejuel
a (Universidad de Cantabria) as part of VCU Geometry and Topology Seminar\
n\n\nAbstract\nGeneralized Geometry was introduced at the beginning of XXI
century by Hitchin\, Gualtieri and Cavalcanti\, as a mathematical theory
including Complex and Symplectic Geometries. The starting points are the
notion of the big tangent bundle\, which is the sum of the tangent and th
e cotangent bundlles of a manifold\, and the notion of generalized almost
complex structure on the big tangent bundle. We shall show that many other
geometric structures appear in Generalized Geometry. The talk will not re
quire deep knowledge of Differential Geometry.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Minyoung Jeon (University of Georgia)
DTSTART;VALUE=DATE-TIME:20221014T170000Z
DTEND;VALUE=DATE-TIME:20221014T175000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/51
DESCRIPTION:Title: Euler characteristic of Brill-Noether loci on Prym varieties\nb
y Minyoung Jeon (University of Georgia) as part of VCU Geometry and Topolo
gy Seminar\n\n\nAbstract\nPrym varieties\, named after Friedrich Prym\, ar
e abelian varieties constructed from étale double covers of algebraic cur
ves. In 1985\, Welters subsequently equipped Prym varieties with Brill-Noe
ther loci. In this talk\, we give a formula for the Euler characteristic o
f the Brill-Noether locus in Prym varieties with a vanishing sequence at o
ne marked point.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Feride Ceren Köse (University of Georgia)
DTSTART;VALUE=DATE-TIME:20230117T150000Z
DTEND;VALUE=DATE-TIME:20230117T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/52
DESCRIPTION:by Feride Ceren Köse (University of Georgia) as part of VCU G
eometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gretchen Matthews (Virginia Tech)
DTSTART;VALUE=DATE-TIME:20230210T150000Z
DTEND;VALUE=DATE-TIME:20230210T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/53
DESCRIPTION:Title: Coding for distributed storage using algebraic geometry\nby Gre
tchen Matthews (Virginia Tech) as part of VCU Geometry and Topology Semina
r\n\n\nAbstract\nGiven the astonishing rates at which data is generated\,
how can it be stored efficiently? How is access to the stored information
guaranteed? How can it be distributed across a network while also protecti
ng it from distortion\, degradation\, and loss? Answers to some of these q
uestions may be found using algebraic geometry. Algebraic geometry codes a
re constructed using curves over finite fields\, a discovery in the 1980s
that motivated much work on curves over finite fields with many rational p
oints and asymptotically good towers of function fields. Refinements of al
gebraic geometry codes designed from curves and surfaces now play a role i
n coding for distributed storage. In this talk\, we share how studying the
se rich underlying structures provides a window into the powerful local pr
operties that aid in designing codes for local recovery from erasures.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lev Borisov (Rutgers University)
DTSTART;VALUE=DATE-TIME:20230217T150000Z
DTEND;VALUE=DATE-TIME:20230217T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/54
DESCRIPTION:Title: On explicit equations of fake projective planes\nby Lev Borisov
(Rutgers University) as part of VCU Geometry and Topology Seminar\n\n\nAb
stract\nFake projective planes are fascinating complex surfaces (real four
-dimensional manifolds). While they were first discovered about 40 years a
go\, their explicit equations have only been computed recently. I will tal
k about the history of fake projective planes and some of the peculiar con
structions and challenges associated with finding their explicit equations
.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sara Maloni (University of Virginia)
DTSTART;VALUE=DATE-TIME:20230224T150000Z
DTEND;VALUE=DATE-TIME:20230224T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/55
DESCRIPTION:Title: Some new results in Higher Teichmüller Theory\nby Sara Maloni
(University of Virginia) as part of VCU Geometry and Topology Seminar\n\n\
nAbstract\nThe Teichmüller space of a surface S is the space of marked hy
perbolic structure on S\, up to equivalence. By considering the holonomy r
epresentation of such structures\, the Teichmüller space can also be seen
as a connected component of (conjugacy classes of) representations from t
he fundamental group of S into PSL(2\,R)\, consisting entirely of discrete
and faithful representations. Generalizing this point of view\, Higher Te
ichmüller Theory studies connected components of (conjugacy classes of) r
epresentations from the fundamental group of S into more general semisimpl
e Lie groups which consist entirely of discrete and faithful representatio
ns.\n\nWe will give a survey of some aspects of Higher Teichmüller Theory
\, and will make links with the recent powerful notion of Anosov represent
ation. Time permitting\, we will conclude by focusing on two separate ques
tions:\nDo these representations correspond to deformation of geometric st
ructures? \nCan we generalize the important notion of pleated surfaces to
higher rank Lie groups like PSL(d\, C)?\nThe answer to question 1 is joint
work with Alessandrini\, Tholozan and Wienhard\, while the answer to ques
tion 2 is joint work with Martone\, Mazzoli and Zhang.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralph Gomez (Swarthmore College)
DTSTART;VALUE=DATE-TIME:20230303T150000Z
DTEND;VALUE=DATE-TIME:20230303T155000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/56
DESCRIPTION:Title: The Berglund-Huebsch Transpose rule and Sasakian Geometry\nby R
alph Gomez (Swarthmore College) as part of VCU Geometry and Topology Semin
ar\n\n\nAbstract\nThe goal of this talk will be to use some ideas from a c
onstruction of mirror Calabi-Yau orbifolds due to Berglund\, Hübsch\, Kra
witz (BHK mirror symmetry) to outline a way to create new examples of Sasa
ki manifolds of positive Ricci curvature. If time permits\, we will say so
me things about the Sasaki-Einstein case and report on (joint with J. Vall
e and J. Vicente) some new examples of Sasaki-Einstein rational homology 7
-spheres.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Beibei Liu (MIT)
DTSTART;VALUE=DATE-TIME:20230317T140000Z
DTEND;VALUE=DATE-TIME:20230317T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/57
DESCRIPTION:Title: Heegaard Floer homology and plane curves with non-cuspidal singular
ities\nby Beibei Liu (MIT) as part of VCU Geometry and Topology Semina
r\n\n\nAbstract\nIt is an interesting question to ask about the possible c
onfigurations of singular points occurring on general algebraic curves. In
this talk\, we use Heegaard Floer homology to study the singularity links
and give some obstructions for the configurations. The main ingredient is
to use the knot Floer complex of the knotification of the singularities l
inks in the algebraic curves. This is joint work with Borodzik and Zemke.\
n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Feride Ceren Köse (University of Georgia)
DTSTART;VALUE=DATE-TIME:20230127T160000Z
DTEND;VALUE=DATE-TIME:20230127T165000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/58
DESCRIPTION:Title: Symmetric unions and knot invariants\nby Feride Ceren Köse (Un
iversity of Georgia) as part of VCU Geometry and Topology Seminar\n\n\nAbs
tract\nWe study symmetric unions in the context of problems regarding knot
invariants. Recently\, a class of symmetric unions was proposed to constr
uct nontrivial knots with trivial Jones polynomial. We show\, however\, th
at such a knot is always trivial and hence this construction cannot be use
d to answer the open question asking whether the Jones polynomial detects
the unknot. We then discuss why symmetric union is a valuable construction
to study knot invariants and why our result provides strong evidence for
the non-existence of nontrivial knots with trivial Jones polynomial.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicola Tarasca (VCU)
DTSTART;VALUE=DATE-TIME:20230324T140000Z
DTEND;VALUE=DATE-TIME:20230324T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/59
DESCRIPTION:Title: Coinvariants of vertex algebras and abelian varieties\nby Nicol
a Tarasca (VCU) as part of VCU Geometry and Topology Seminar\n\n\nAbstract
\nSpaces of coinvariants have classically been constructed by assigning re
presentations of affine Lie algebras\, and more generally\, vertex operato
r algebras\, to algebraic curves.\nRemoving curves out of the picture\, I
will introduce spaces of coinvariants at abelian varieties with respect to
the action of an infinite-dimensional Lie algebra. I will show how these
spaces globalize to twisted D-modules on moduli of abelian varieties\, ext
ending the classical picture from moduli of curves. This is based on my re
cent preprint arXiv:2301.13227.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Almut Burchard (University of Toronto)
DTSTART;VALUE=DATE-TIME:20230331T140000Z
DTEND;VALUE=DATE-TIME:20230331T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/60
DESCRIPTION:Title: What is the best shape? Geometric problems arising in aggregation m
odels\nby Almut Burchard (University of Toronto) as part of VCU Geomet
ry and Topology Seminar\n\n\nAbstract\nHow do pair interactions shape the
large-scale behaviour of a\ncloud of particles (animals\, social agents ..
.) ? In the most basic\nmodels\, the shape of the cloud is determined by
minimizing an\nattractive-repulsive interaction energy under suitable geom
etric\nconstraints.\nWhen can we expect aggregation to occur? What is the
shape of the\nresulting flock? I will describe recent work on optimal sha
pes in\ncapacitor problems that occur as limiting cases.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ihsan Topaloglu (VCU)
DTSTART;VALUE=DATE-TIME:20230407T140000Z
DTEND;VALUE=DATE-TIME:20230407T145000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/61
DESCRIPTION:Title: Characterization of regular polygons via an overdetermined problem<
/a>\nby Ihsan Topaloglu (VCU) as part of VCU Geometry and Topology Seminar
\n\n\nAbstract\nIn this talk I will discuss the optimality of regular tria
ngles and quadrilaterals for nonlocal energies of generalized Riesz-type i
n the class of polygons with a fixed number of sides and fixed area\, as w
ell as their characterization as unique stationary points. These results a
re joint work with M. Bonacini and R. Cristoferi. I will also present on r
ecent results by Bogosel\, Bucur and Fragalà where they show that for cer
tain interaction kernels there is symmetry breaking for polygons with numb
er of sides greater than 5.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Louisa Liles (UVA)
DTSTART;VALUE=DATE-TIME:20230915T170000Z
DTEND;VALUE=DATE-TIME:20230915T175000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/62
DESCRIPTION:Title: Quantum modularity of 3-manifold invariants\nby Louisa Liles (U
VA) as part of VCU Geometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Prakash Belkale (UNC Chapel Hill)
DTSTART;VALUE=DATE-TIME:20230929T170000Z
DTEND;VALUE=DATE-TIME:20230929T175000Z
DTSTAMP;VALUE=DATE-TIME:20230925T233521Z
UID:vcugeomandtop/63
DESCRIPTION:Title: Vertices in the multiplicative eigenvalue problem\nby Prakash B
elkale (UNC Chapel Hill) as part of VCU Geometry and Topology Seminar\n\n\
nAbstract\nThe classical problem about the possible eigenvalues of a prod
uct of unitary matrices AB given the eigenvalues of A and B has relations
to many areas of geometry\, representation theory and combinatorics. There
is a polytope controlling this problem whose faces can be described in te
rms of the quantum cohomology of Grassmannians. The problem of determining
the vertices of the polytope remained open for a long time\, but recently
I gave an inductive framework for understanding vertices on a given face
: some vertices come explicitly from cycle classes of geometrically defin
ed loci\, and the remaining vertices come from an induction procedure fro
m smaller groups. I want to describe this method\, and generalization to t
he case of arbitrary groups (joint work with Joshua Kiers). If time permi
ts\, I will state connections to the theory of unitary rigid local systems
.\n
LOCATION:https://researchseminars.org/talk/vcugeomandtop/63/
END:VEVENT
END:VCALENDAR