BEGIN:VCALENDAR
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BEGIN:VEVENT
SUMMARY:Yan Soibelman (Kansas State University)
DTSTART:20200504T191000Z
DTEND:20200504T203000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/1
DESCRIPTION:Title: Cohomological Hall Algebras\, Instantons and Vertex Alg
ebras\nby Yan Soibelman (Kansas State University) as part of Informal
string-math seminar\n\n\nAbstract\nOriginally the notion of Cohomological
Hall algebra (COHA for short) was introduced in my joint paper with Maxim
Kontsevich (arXiv: 1006.2706) for the\npurposes of motivic Donaldson-Thoma
s theory of 3-dimensional Calabi-Yau categories.\nA physicist can think in
formally of COHA as of quantized enveloping algebra of the Lie algebra of
single-particle closed BPS states.\nFrom this point of view there should b
e a class of representations of COHA associated with spaces of open BPS st
ates. Mathematically\nwe are talking about representations of COHAs in the
cohomology of the moduli spaces of stable framed objects of the category
(e.g. stable framed coherent sheaves on a Calabi-Yau 3-fold).\n\nI am goin
g to discuss recent results which relate this class of representations to
the (generalization of the ) AGT conjecture.\nIn particular\, a version of
COHA of the category of torsion sheaves on the standard complex 3-dimensi
onal vector space acts on the cohomology of the moduli space of Nekrasov
spiked instantons. This action can be upgraded to the action on this space
of the ``vertex algebra at the corner" of Gaiotto and Rapcak.\nThe underl
ying geometry is the one of non-reduced toric divisors in toric Calabi-Yau
3-folds.\nThe above-mentioned result is yet another incarnation of the i
dea that quantum algebras which initially might look as ``2-dimensional ob
jects" (e.g. quiver Yangians) should be upgraded\nto those in dimension 3.
\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andy Neitzke (Yale University)
DTSTART:20200525T191000Z
DTEND:20200525T204000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/2
DESCRIPTION:Title: Abelianization of flat connections\, and its q-deformat
ion\nby Andy Neitzke (Yale University) as part of Informal string-math
seminar\n\n\nAbstract\nAbelianization of flat connections is a constructi
on motivated by\nsupersymmetric quantum field theory\, which has turned ou
t to be connected to\nvarious bits of geometry -- in particular\, to Donal
dson-Thomas theory\, cluster\nalgebra\, the exact WKB method for analysis
of ODEs\, and hyperkahler geometry.\nIn some of these subjects it is known
that there exists a natural\nq-deformation which takes us from the commut
ative to the noncommutative world.\nThis suggests that there ought to exis
t a q-deformation of abelianization as\nwell. I will explain joint work in
progress with Fei Yan on constructing this\nq-deformation in a geometric
way using spectral networks. This construction is\ninspired by related wor
k by various authors\, especially Bonahon-Wong\, Gabella\,\nGaiotto-Witten
. One byproduct is a new scheme for computing known polynomial\ninvariants
of links in R^3\, which generalizes the usual "vertex models".\n\nThe zoo
m link \n\nhttps://berkeley.zoom.us/j/93328405860?pwd=Um1GbHBCSUJMdUlWWnd0
ZVMxQmwwdz09\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anton Zeitlin (Louisiana State University)
DTSTART:20200608T191000Z
DTEND:20200608T204000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/3
DESCRIPTION:Title: Geometry of Bethe Equations and q-Opers\nby Anton Z
eitlin (Louisiana State University) as part of Informal string-math semina
r\n\n\nAbstract\nIntegrable models are known to keep reemerging over time
in various mathematical incarnations. Recently\, such models based on qu
antum groups naturally appeared in the framework of enumerative geometry.
In this context the so-called Bethe ansatz equations\, instrumental for fi
nding the spectrum of the XXZ model Hamiltonian\, naturally show up as con
straints for the quantum K-theory ring of quiver varieties. \n\nIn this ta
lk I will describe another geometric interpretation of Bethe ansatz equati
ons\, which is indirectly related to the above. I will introduce the notio
n of (G\,q)-opers\, the difference analogue of oper connections for simply
connected group G. I will explain the one-to-one correspondence between (
G\,q)-opers of specific kind and Bethe equations for XXZ models. The key e
lement in this identification is the so-called QQ-system\, which has previ
ously appeared in the study of ODE/IM correspondence and the Grothendieck
ring of the category O of the relevant quantum algebras. \nI will specula
te on how that fits into recently proposed quantum q-Langlands corresponde
nce by M. Aganаgic\, E. Frenkel and A. Okounkov.\n\nThe talk is based on
joint work with E. Frenkel\, P. Koroteev and D. Sage ( arXiv:1811.09937\,
arXiv:2002.07344)\n\nzoom link: https://berkeley.zoom.us/j/93328405860?pwd
=Um1GbHBCSUJMdUlWWnd0ZVMxQmwwdz09\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marcos Marino (University of Geneva)
DTSTART:20200622T191000Z
DTEND:20200622T204000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/4
DESCRIPTION:Title: Spectral theory of quantum curves and topological strin
gs\nby Marcos Marino (University of Geneva) as part of Informal string
-math seminar\n\n\nAbstract\nMany problems in mathematical physics\, from
the WKB method to knot theory\, involve quantum versions of algebraic curv
es. \nIn this talk I will review an approach to the quantization of local
mirror curves which makes it possible to reconstruct \ntopological string
theory on toric Calabi-Yau manifolds. In this approach\, the quantization
of the mirror curve \nleads to a trace class operator on the real line. Th
e Fredholm determinant and spectral traces of this operator turn out to \n
encode the topological string partition functions. Conversely\, one can us
e enumerative invariants to solve the spectral theory of these operators\,
which \nleads to new exact results in quantum mechanics.\n\nZoom link:\nh
ttps://berkeley.zoom.us/j/93328405860?pwd=Um1GbHBCSUJMdUlWWnd0ZVMxQmwwdz09
\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Okounkov (Columbia University)
DTSTART:20200706T211000Z
DTEND:20200706T230000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/5
DESCRIPTION:Title: Inductive construction of stable envelopes and applicat
ions\nby Andrei Okounkov (Columbia University) as part of Informal str
ing-math seminar\n\nAbstract: TBA\n\nberkeley.zoom.us/j/93328405860?pwd=Um
1GbHBCSUJMdUlWWnd0ZVMxQmwwdz09\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Okounkov (Columbia University)
DTSTART:20200803T211000Z
DTEND:20200803T234000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/6
DESCRIPTION:Title: Inductive construction of stable envelopes and applicat
ions II\nby Andrei Okounkov (Columbia University) as part of Informal
string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Shapiro (University of Notre Dame)
DTSTART:20200831T201000Z
DTEND:20200831T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/7
DESCRIPTION:Title: Cluster structure on K-theoretic Coulomb branches\n
by Alexander Shapiro (University of Notre Dame) as part of Informal string
-math seminar\n\n\nAbstract\nBraverman\, Finkelberg\, and Nakajima define
the K-theoretic Coulomb branch of a 3d $\\mathcal N=4$ SUSY gauge theory a
s the affine variety $\\mathcal M_{G\,N}$ arising as the equivariant K-the
ory of certain moduli space $\\mathscr R_{G\,N}$\, labelled by the complex
reductive group $G$ and its complex representation $N$. It was conjecture
d by Gaiotto\, that (quantized) K-theoretic Coulomb branches bear the stru
cture of (quantum) cluster varieties. I will outline a proof of this conje
cture for quiver gauge theories\, and show how the cluster structure allow
s to count the BPS states (aka DT-invariants) of the theory. Time permitti
ng\, I will also show how the above cluster structure relates to positive
and Gelfand-Tsetlin representations of quantum groups\, and higher rank Fe
nchel–Nielsen coordinates on moduli spaces of $PGL_n$ local systems. Thi
s talk is based on joint works with Gus Schrader.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Max Zimet (Harvard University)
DTSTART:20200914T191000Z
DTEND:20200914T204000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/8
DESCRIPTION:Title: K3 Metrics\nby Max Zimet (Harvard University) as pa
rt of Informal string-math seminar\n\n\nAbstract\nI will explain a physica
lly motivated construction of Ricci-flat K3 metrics via a hyper-Kahler quo
tient\, which yields the first examples of explicit Ricci-flat metrics on
compact non-toroidal Calabi-Yau manifolds. I will also relate it - both ph
ysically and mathematically - to a second such construction\, which is as
yet not completely explicit: the missing data is the BPS index of a little
string theory on T^2. Via string dualities\, we can reformulate this data
in terms of both open string reduced Gromov-Witten theory of K3 and gener
alized Donaldson-Thomas theory of an auxiliary non-compact threefold. I wi
ll show that these invariants may be extracted from the metrics produced b
y the first approach.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wei Gu (Harvard University)
DTSTART:20200928T201000Z
DTEND:20200928T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/9
DESCRIPTION:Title: A proposal for nonabelian mirrors\nby Wei Gu (Harva
rd University) as part of Informal string-math seminar\n\n\nAbstract\nThis
talk is concerned with non-abelian mirrors. We define (non)abelian gauged
linear sigma models (GLSMs) by providing some data first\, and then we st
udy T-dual theories of GLSMs. The construction of nonabelian mirrors is re
lated to abelian mirrors construction found by Hori and Vafa in 2000. Thus
\, we will review abelian mirrors first and then give a framework for nona
belian mirrors. Two concrete examples will be discussed in the talk\, the
projective space and Grassmannian. Finally\, I will briefly summarize some
applications of nonabelian mirrors such as 2d Hori-Seiberg duals in mirro
rs\, mirrors of pure gauge theories.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tomoyuki Arakawa (Kyoto University)
DTSTART:20201005T221000Z
DTEND:20201006T004000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/10
DESCRIPTION:Title: 4D/2D duality and representation theory\nby Tomoyu
ki Arakawa (Kyoto University) as part of Informal string-math seminar\n\nA
bstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joerg Teschner (DESY)
DTSTART:20201019T201000Z
DTEND:20201019T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/11
DESCRIPTION:Title: Proposal for a geometric characterisation of topologic
al string partition functions\nby Joerg Teschner (DESY) as part of Inf
ormal string-math seminar\n\n\nAbstract\nWe propose a geometric characteri
sation of the topological string partition functions associated to the loc
al Calabi-Yau (CY) manifolds used in the geometric engineering of d = 4\,
N = 2 supersymmetric field theories of class S. A quantisation of these CY
manifolds defines differential operators called quantum curves. The parti
tion functions are extracted from the isomonodromic tau-functions associat
ed to the quantum curves by expansions of generalised theta series type. I
t turns out that the partition functions are in one-to-one correspondence
with preferred coordinates on the moduli spaces of quantum curves defined
using the Exact WKB method. The coordinates defined in this way jump acros
s certain loci in the moduli space. The changes of normalisation of the ta
u-functions associated to these jumps define a natural line bundle.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Masahito Yamazaki (Kavli IPMU)
DTSTART:20201026T201000Z
DTEND:20201026T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/12
DESCRIPTION:Title: Quiver Yangians and Crystal Melting\nby Masahito Y
amazaki (Kavli IPMU) as part of Informal string-math seminar\n\n\nAbstract
\nWhile the BPS state counting problem in general toric Calabi-Yau manifol
ds was solved a decade ago\, it has long remained an unsolved problem to i
dentify the underlying BPS state algebra. Recently\, we solved this proble
m by introducing a new infinite-dimensional algebra\, the BPS quiver Yangi
an. We constructed representations of the algebra in terms of crystal melt
ing\, and derived the representations physically from supersymmetric quant
um mechanics. This talk is based on two papers arXiv:2003.08909 and arXiv:
2008.07006\, in collaboration with Wei Li and Dmitry Galakhov.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pierrick Bousseau (ETH\, Zurich)
DTSTART:20201102T211000Z
DTEND:20201102T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/13
DESCRIPTION:Title: Refined holomorphic anomaly equation for local P^2
\nby Pierrick Bousseau (ETH\, Zurich) as part of Informal string-math semi
nar\n\n\nAbstract\nIt is a general expectation that the refined topologica
l string theory of local Calabi-Yau 3-folds produces quasimodular forms wh
ich are solutions of some refined holomorphic anomaly equation. I will pre
sent a mathematical derivation that it is indeed the case for the refined
topological string on local P^2 in the Nekrasov-Shatashvili limit. The rat
her indirect proof exploits mathematical incarnations of various string du
alities. Along the way\, I will present a new way to compute the D4-D2-D0
BPS spectrum of local P^2 in the large volume limit. Work partly joint wit
h Honglu Fan\, Shuai Guo\, and Longting Wu.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Haouzi (SCGP)
DTSTART:20201109T211000Z
DTEND:20201109T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/14
DESCRIPTION:Title: Non-Perturbative Schwinger-Dyson Equations for 3d N =
4 Gauge Theories\nby Nathan Haouzi (SCGP) as part of Informal string-m
ath seminar\n\n\nAbstract\nWe analyze symmetries corresponding to separate
d topological sectors of 3d N= 4 gauge theories with Higgs vacua\, compact
ified on a circle. The symmetries are encoded in Schwinger-Dyson identitie
s satisfied by correlation functions of a certain gauge-invariant operator
\, the "vortex character." Such a character observable is realized as the
vortex partition function of the 3d gauge theory\, in the presence of a 1/
2-BPS line defect. The character enjoys a double refinement\, interpreted
as a deformation of the usual characters of finite-dimensional representat
ions of quantum affine algebras. We derive and interpret the Schwinger-Dys
on identities from various physical perspectives: in the context of the 3d
gauge theory itself\, in a 1d gauged quantum mechanics\, in 2d q-Toda the
ory\, and in 6d little string theory. We establish the dictionary between
all approaches.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joerg Teschner (DESY)
DTSTART:20201116T211000Z
DTEND:20201116T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/15
DESCRIPTION:Title: Proposal for a geometric characterisation of topologic
al string partition functions\, part II\nby Joerg Teschner (DESY) as p
art of Informal string-math seminar\n\n\nAbstract\nAbstract: In the second
part of my talk I would start by giving a reasonably brief summary of the
first part\, followed by a discussion of the known or expected relations
to some other lines of research\, which could include (a selection of) the
following points:\n\nRelation to geometry of hypermultiplet moduli spaces
\nRelation to the spectrum of BPS-states\, geometry of space of stability
conditions\nRelation classical-quantum\nRelation with Theta-functions on i
ntermediate Jacobian fibration\nInterplay between 2d-4d wall-crossing and
free fermion picture.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrew Manion (University of Southern California)
DTSTART:20201123T211000Z
DTEND:20201123T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/16
DESCRIPTION:Title: Higher representations and cornered Heegaard Floer hom
ology\nby Andrew Manion (University of Southern California) as part of
Informal string-math seminar\n\n\nAbstract\nStarting with some context an
d motivation from a mathematical and physical perspective\, I will discuss
recent work with Raphael Rouquier on a higher tensor product operation fo
r 2-representations of Khovanov's categorification of U(gl(1|1)^+)\, examp
les of such 2-representations that arise as strands algebras in bordered a
nd cornered Heegaard Floer homology\, and a tensor-product-based gluing fo
rmula for these 2-representations expanding on work of Douglas-Manolescu.\
n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miroslav Rapcak (UC Berkeley)
DTSTART:20201130T211000Z
DTEND:20201130T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/17
DESCRIPTION:Title: Miura Operators\, Degenerate Fields and the M2-M5 Inte
rsection\nby Miroslav Rapcak (UC Berkeley) as part of Informal string-
math seminar\n\n\nAbstract\nStacks of M2-branes in Omega background lead t
o a class of Coulomb branch algebras due to Kodera and Nakajima. On the ot
her hand\, stacks of M5-branes in Omega background lead to a class of vert
ex operator algebras due to a version of the AGT correspondence. I will pr
ovide a new interpretation of key objects in the theory of vertex operator
algebras\, such as Miura operators and degenerate fields\, as describing
various junctions of M2 and M5 branes in M-theory. The new perspective lea
ds to a rather close interplay between the relevant class of Coulomb branc
h algebras and vertex operator algebras with many striking consequences.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikita Nekrasov (Simons Center)
DTSTART:20210125T211000Z
DTEND:20210125T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/18
DESCRIPTION:Title: Beneath the surface: Knizhnik-Zamolodchikov equation i
n four dimensions\nby Nikita Nekrasov (Simons Center) as part of Infor
mal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Davide Gaiotto (Perimeter Institute)
DTSTART:20210201T211000Z
DTEND:20210201T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/19
DESCRIPTION:Title: Vertex operators and screening charges as gauge-invari
ant brane intersections in twisted M-theory\nby Davide Gaiotto (Perime
ter Institute) as part of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Benoit Vicedo (University of York)
DTSTART:20210208T211000Z
DTEND:20210208T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/20
DESCRIPTION:by Benoit Vicedo (University of York) as part of Informal stri
ng-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Horava (UC Berkeley)
DTSTART:20210222T211000Z
DTEND:20210222T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/21
DESCRIPTION:Title: Topological Quantum Gravity of Perelman's Ricci Flow\nby Petr Horava (UC Berkeley) as part of Informal string-math seminar\n
\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Brini (University of Sheffield)
DTSTART:20210301T211000Z
DTEND:20210301T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/22
DESCRIPTION:Title: Quantum geometry and physics of Looijenga pairs\nb
y Andrea Brini (University of Sheffield) as part of Informal string-math s
eminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tobias Ekholm (Uppsala University)
DTSTART:20210308T211000Z
DTEND:20210308T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/23
DESCRIPTION:Title: Knot conormals\, quantum curves\, holomorphic disks\,
and quivers\nby Tobias Ekholm (Uppsala University) as part of Informal
string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivan Danilenko (UC Berkeley)
DTSTART:20210329T211000Z
DTEND:20210329T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/24
DESCRIPTION:Title: Quantum Cohomology and Slices of the Affine Grassmanni
an\nby Ivan Danilenko (UC Berkeley) as part of Informal string-math se
minar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vivek Shende (UC Berkeley)
DTSTART:20210315T201000Z
DTEND:20210315T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/25
DESCRIPTION:Title: Gluing the mirror\nby Vivek Shende (UC Berkeley) a
s part of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hiraku Nakajima
DTSTART:20210405T211000Z
DTEND:20210405T224000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/26
DESCRIPTION:Title: Geometric Satake for affine Lie algebras\nby Hirak
u Nakajima as part of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mykola Dedushenko
DTSTART:20210503T201000Z
DTEND:20210503T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/28
DESCRIPTION:Title: Stable envelopes and Janus: a QFT home for some geomet
ric constructions\nby Mykola Dedushenko as part of Informal string-mat
h seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Taro Kimura
DTSTART:20210510T201000Z
DTEND:20210510T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/29
DESCRIPTION:Title: Aspects of supergroup gauge theory\nby Taro Kimura
as part of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pavel Etingof
DTSTART:20210419T201000Z
DTEND:20210419T214000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/30
DESCRIPTION:by Pavel Etingof as part of Informal string-math seminar\n\nAb
stract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Peter Koroteev (UC Berkeley)
DTSTART:20211011T211000Z
DTEND:20211011T230000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/31
DESCRIPTION:Title: q-Opers\, QQ-Systems and Bethe Ansatz II\nby Peter
Koroteev (UC Berkeley) as part of Informal string-math seminar\n\n\nAbstr
act\nWe introduce the notions of (G\,q)-opers and Miura (G\,q)-opers\, whe
re G is a simply-connected complex simple Lie group\, and prove some gener
al results about their structure. We then establish a one-to-one correspon
dence between the set of (G\,q)-opers of a certain kind and the set of non
degenerate solutions of a system of Bethe Ansatz equations. Additionally w
e associate to a (G\,q)-oper a class of meromorphic sections of a G-bundle
\, satisfying certain difference equations\, which we refer to as generali
zed q-Wronskians. We show that the QQ-systems and their extensions emerge
as the relations between generalized minors\, thereby putting the Bethe An
satz equations in the framework of cluster mutations known in the theory o
f double Bruhat cells.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (Institute for Advanced Study)
DTSTART:20211018T211000Z
DTEND:20211018T230000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/32
DESCRIPTION:Title: Complex Metrics in Spacetime\nby Edward Witten (In
stitute for Advanced Study) as part of Informal string-math seminar\n\n\nA
bstract\nIn the ``Euclidean'' approach to quantum gravity\, it sometimes s
eems useful to include complex saddle points. But what class of complex sp
acetime metrics is physically sensible? That will be the topic of this lec
ture.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ben Webster (Perimeter Institute)
DTSTART:20211025T211000Z
DTEND:20211025T230000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/33
DESCRIPTION:by Ben Webster (Perimeter Institute) as part of Informal strin
g-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Richard Thomas (Imperial College\, London)
DTSTART:20211101T201000Z
DTEND:20211101T220000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/34
DESCRIPTION:Title: Nonabelian DT theory from abelian\nby Richard Thom
as (Imperial College\, London) as part of Informal string-math seminar\n\n
\nAbstract\nFix a Calabi-Yau 3-fold X. Its DT invariants count stable bund
les and sheaves on X. The generalised DT invariants of Joyce-Song count se
mistable bundles and sheaves on X. I will describe work with Soheyla Feyzb
akhsh showing these generalised DT invariants in any rank r can be written
in terms of rank 1 invariants.\n\nBy the MNOP conjecture these rank 1 “
abelian” invariants are determined by the GW invariants of X. Along the
way we also express rank r DT invariants in terms of invariants counting D
4-D2-D0 branes: rank 0 sheaves supported on surfaces in X. These invariant
s are predicted by S-duality to be governed by (vector-valued\, mock) modu
lar forms.\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joerg Teschner (DESY)
DTSTART:20211108T201000Z
DTEND:20211108T220000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/35
DESCRIPTION:by Joerg Teschner (DESY) as part of Informal string-math semin
ar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ina Petkova (Dartmouth College)
DTSTART:20211115T223000Z
DTEND:20211116T003000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/36
DESCRIPTION:by Ina Petkova (Dartmouth College) as part of Informal string-
math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michele Del Zotto (University of Durham)
DTSTART:20211129T221000Z
DTEND:20211130T000000Z
DTSTAMP:20260404T110645Z
UID:BerkeleyStringMathe/37
DESCRIPTION:by Michele Del Zotto (University of Durham) as part of Informa
l string-math seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/BerkeleyStringMathe/37/
END:VEVENT
END:VCALENDAR