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BEGIN:VEVENT
SUMMARY:Yan Soibelman (Kansas State University)
DTSTART:20200504T191000Z
DTEND:20200504T203000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/1
DESCRIPTION:Title: Cohomological Hall Algebras\, Instantons and Vertex Algebras\nby Yan Soibelman (Kansas State University) as part of Informal string-
math seminar\n\n\nAbstract\nOriginally the notion of Cohomological Hall al
gebra (COHA for short) was introduced in my joint paper with Maxim Kontsev
ich (arXiv: 1006.2706) for the\npurposes of motivic Donaldson-Thomas theor
y of 3-dimensional Calabi-Yau categories.\nA physicist can think informall
y of COHA as of quantized enveloping algebra of the Lie algebra of single-
particle closed BPS states.\nFrom this point of view there should be a cla
ss of representations of COHA associated with spaces of open BPS states. M
athematically\nwe are talking about representations of COHAs in the cohomo
logy of the moduli spaces of stable framed objects of the category (e.g. s
table framed coherent sheaves on a Calabi-Yau 3-fold).\n\nI am going to di
scuss recent results which relate this class of representations to the (ge
neralization of the ) AGT conjecture.\nIn particular\, a version of COHA o
f the category of torsion sheaves on the standard complex 3-dimensional ve
ctor 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 underlying ge
ometry is the one of non-reduced toric divisors in toric Calabi-Yau 3-fold
s.\nThe above-mentioned result is yet another incarnation of the idea tha
t quantum algebras which initially might look as ``2-dimensional objects"
(e.g. quiver Yangians) should be upgraded\nto those in dimension 3.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andy Neitzke (Yale University)
DTSTART:20200525T191000Z
DTEND:20200525T204000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/2
DESCRIPTION:Title: Abelianization of flat connections\, and its q-deformation
\nby Andy Neitzke (Yale University) as part of Informal string-math semina
r\n\n\nAbstract\nAbelianization of flat connections is a construction moti
vated by\nsupersymmetric quantum field theory\, which has turned out to be
connected to\nvarious bits of geometry -- in particular\, to Donaldson-Th
omas theory\, cluster\nalgebra\, the exact WKB method for analysis of ODEs
\, and hyperkahler geometry.\nIn some of these subjects it is known that t
here exists a natural\nq-deformation which takes us from the commutative t
o the noncommutative world.\nThis suggests that there ought to exist a q-d
eformation of abelianization as\nwell. I will explain joint work in progre
ss with Fei Yan on constructing this\nq-deformation in a geometric way usi
ng spectral networks. This construction is\ninspired by related work by va
rious authors\, especially Bonahon-Wong\, Gabella\,\nGaiotto-Witten. One b
yproduct is a new scheme for computing known polynomial\ninvariants of lin
ks in R^3\, which generalizes the usual "vertex models".\n\nThe zoom link
\n\nhttps://berkeley.zoom.us/j/93328405860?pwd=Um1GbHBCSUJMdUlWWnd0ZVMxQmw
wdz09\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anton Zeitlin (Louisiana State University)
DTSTART:20200608T191000Z
DTEND:20200608T204000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/3
DESCRIPTION:Title: Geometry of Bethe Equations and q-Opers\nby Anton Zeitlin
(Louisiana State University) as part of Informal string-math seminar\n\n\n
Abstract\nIntegrable models are known to keep reemerging over time in var
ious mathematical incarnations. Recently\, such models based on quantum g
roups naturally appeared in the framework of enumerative geometry. In this
context the so-called Bethe ansatz equations\, instrumental for finding t
he spectrum of the XXZ model Hamiltonian\, naturally show up as constraint
s for the quantum K-theory ring of quiver varieties. \n\nIn this talk I wi
ll describe another geometric interpretation of Bethe ansatz equations\, w
hich is indirectly related to the above. I will introduce the notion of (G
\,q)-opers\, the difference analogue of oper connections for simply connec
ted group G. I will explain the one-to-one correspondence between (G\,q)-o
pers of specific kind and Bethe equations for XXZ models. The key element
in this identification is the so-called QQ-system\, which has previously a
ppeared in the study of ODE/IM correspondence and the Grothendieck ring of
the category O of the relevant quantum algebras. \nI will speculate on h
ow that fits into recently proposed quantum q-Langlands correspondence by
M. Aganаgic\, E. Frenkel and A. Okounkov.\n\nThe talk is based on joint w
ork with E. Frenkel\, P. Koroteev and D. Sage ( arXiv:1811.09937\, arXiv:2
002.07344)\n\nzoom link: https://berkeley.zoom.us/j/93328405860?pwd=Um1GbH
BCSUJMdUlWWnd0ZVMxQmwwdz09\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marcos Marino (University of Geneva)
DTSTART:20200622T191000Z
DTEND:20200622T204000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/4
DESCRIPTION:Title: Spectral theory of quantum curves and topological strings\
nby Marcos Marino (University of Geneva) as part of Informal string-math s
eminar\n\n\nAbstract\nMany problems in mathematical physics\, from the WKB
method to knot theory\, involve quantum versions of algebraic curves. \nI
n 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. The Fredh
olm determinant and spectral traces of this operator turn out to \nencode
the topological string partition functions. Conversely\, one can use enume
rative invariants to solve the spectral theory of these operators\, which
\nleads to new exact results in quantum mechanics.\n\nZoom link:\nhttps://
berkeley.zoom.us/j/93328405860?pwd=Um1GbHBCSUJMdUlWWnd0ZVMxQmwwdz09\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Okounkov (Columbia University)
DTSTART:20200706T211000Z
DTEND:20200706T230000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/5
DESCRIPTION:Title: Inductive construction of stable envelopes and applications\nby Andrei Okounkov (Columbia University) as part of Informal string-mat
h seminar\n\nAbstract: TBA\n\nberkeley.zoom.us/j/93328405860?pwd=Um1GbHBCS
UJMdUlWWnd0ZVMxQmwwdz09\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrei Okounkov (Columbia University)
DTSTART:20200803T211000Z
DTEND:20200803T234000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/6
DESCRIPTION:Title: Inductive construction of stable envelopes and applications II
\nby Andrei Okounkov (Columbia University) as part of Informal string-
math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Shapiro (University of Notre Dame)
DTSTART:20200831T201000Z
DTEND:20200831T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/7
DESCRIPTION:Title: Cluster structure on K-theoretic Coulomb branches\nby Alex
ander Shapiro (University of Notre Dame) as part of Informal string-math s
eminar\n\n\nAbstract\nBraverman\, Finkelberg\, and Nakajima define the K-t
heoretic Coulomb branch of a 3d $\\mathcal N=4$ SUSY gauge theory as the a
ffine variety $\\mathcal M_{G\,N}$ arising as the equivariant K-theory of
certain moduli space $\\mathscr R_{G\,N}$\, labelled by the complex reduct
ive group $G$ and its complex representation $N$. It was conjectured by Ga
iotto\, that (quantized) K-theoretic Coulomb branches bear the structure o
f (quantum) cluster varieties. I will outline a proof of this conjecture f
or quiver gauge theories\, and show how the cluster structure allows to co
unt the BPS states (aka DT-invariants) of the theory. Time permitting\, I
will also show how the above cluster structure relates to positive and Gel
fand-Tsetlin representations of quantum groups\, and higher rank Fenchel
–Nielsen coordinates on moduli spaces of $PGL_n$ local systems. This tal
k is based on joint works with Gus Schrader.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Max Zimet (Harvard University)
DTSTART:20200914T191000Z
DTEND:20200914T204000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/8
DESCRIPTION:Title: K3 Metrics\nby Max Zimet (Harvard University) as part of I
nformal string-math seminar\n\n\nAbstract\nI will explain a physically mot
ivated construction of Ricci-flat K3 metrics via a hyper-Kahler quotient\,
which yields the first examples of explicit Ricci-flat metrics on compact
non-toroidal Calabi-Yau manifolds. I will also relate it - both physicall
y 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 ter
ms of both open string reduced Gromov-Witten theory of K3 and generalized
Donaldson-Thomas theory of an auxiliary non-compact threefold. I will show
that these invariants may be extracted from the metrics produced by the f
irst approach.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wei Gu (Harvard University)
DTSTART:20200928T201000Z
DTEND:20200928T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/9
DESCRIPTION:Title: A proposal for nonabelian mirrors\nby Wei Gu (Harvard Univ
ersity) as part of Informal string-math seminar\n\n\nAbstract\nThis talk i
s concerned with non-abelian mirrors. We define (non)abelian gauged linear
sigma models (GLSMs) by providing some data first\, and then we study T-d
ual theories of GLSMs. The construction of nonabelian mirrors is related t
o abelian mirrors construction found by Hori and Vafa in 2000. Thus\, we w
ill review abelian mirrors first and then give a framework for nonabelian
mirrors. Two concrete examples will be discussed in the talk\, the project
ive space and Grassmannian. Finally\, I will briefly summarize some applic
ations of nonabelian mirrors such as 2d Hori-Seiberg duals in mirrors\, mi
rrors of pure gauge theories.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tomoyuki Arakawa (Kyoto University)
DTSTART:20201005T221000Z
DTEND:20201006T004000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/10
DESCRIPTION:Title: 4D/2D duality and representation theory\nby Tomoyuki Arak
awa (Kyoto University) as part of Informal string-math seminar\n\nAbstract
: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joerg Teschner (DESY)
DTSTART:20201019T201000Z
DTEND:20201019T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/11
DESCRIPTION:Title: Proposal for a geometric characterisation of topological stri
ng partition functions\nby Joerg Teschner (DESY) as part of Informal s
tring-math seminar\n\n\nAbstract\nWe propose a geometric characterisation
of the topological string partition functions associated to the local Cala
bi-Yau (CY) manifolds used in the geometric engineering of d = 4\, N = 2 s
upersymmetric field theories of class S. A quantisation of these CY manifo
lds defines differential operators called quantum curves. The partition fu
nctions are extracted from the isomonodromic tau-functions associated to t
he quantum curves by expansions of generalised theta series type. It turns
out that the partition functions are in one-to-one correspondence with pr
eferred coordinates on the moduli spaces of quantum curves defined using t
he Exact WKB method. The coordinates defined in this way jump across certa
in loci in the moduli space. The changes of normalisation of the tau-funct
ions associated to these jumps define a natural line bundle.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Masahito Yamazaki (Kavli IPMU)
DTSTART:20201026T201000Z
DTEND:20201026T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/12
DESCRIPTION:Title: Quiver Yangians and Crystal Melting\nby Masahito Yamazaki
(Kavli IPMU) as part of Informal string-math seminar\n\n\nAbstract\nWhile
the BPS state counting problem in general toric Calabi-Yau manifolds was
solved a decade ago\, it has long remained an unsolved problem to identify
the underlying BPS state algebra. Recently\, we solved this problem by in
troducing a new infinite-dimensional algebra\, the BPS quiver Yangian. We
constructed representations of the algebra in terms of crystal melting\, a
nd derived the representations physically from supersymmetric quantum mech
anics. This talk is based on two papers arXiv:2003.08909 and arXiv:2008.07
006\, in collaboration with Wei Li and Dmitry Galakhov.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pierrick Bousseau (ETH\, Zurich)
DTSTART:20201102T211000Z
DTEND:20201102T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/13
DESCRIPTION:Title: Refined holomorphic anomaly equation for local P^2\nby Pi
errick Bousseau (ETH\, Zurich) as part of Informal string-math seminar\n\n
\nAbstract\nIt is a general expectation that the refined topological strin
g theory of local Calabi-Yau 3-folds produces quasimodular forms which are
solutions of some refined holomorphic anomaly equation. I will present a
mathematical derivation that it is indeed the case for the refined topolog
ical string on local P^2 in the Nekrasov-Shatashvili limit. The rather ind
irect proof exploits mathematical incarnations of various string dualities
. Along the way\, I will present a new way to compute the D4-D2-D0 BPS spe
ctrum of local P^2 in the large volume limit. Work partly joint with Hongl
u Fan\, Shuai Guo\, and Longting Wu.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Haouzi (SCGP)
DTSTART:20201109T211000Z
DTEND:20201109T224000Z
DTSTAMP:20260422T212527Z
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-math sem
inar\n\n\nAbstract\nWe analyze symmetries corresponding to separated topol
ogical sectors of 3d N= 4 gauge theories with Higgs vacua\, compactified o
n a circle. The symmetries are encoded in Schwinger-Dyson identities satis
fied 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 l
ine defect. The character enjoys a double refinement\, interpreted as a de
formation of the usual characters of finite-dimensional representations of
quantum affine algebras. We derive and interpret the Schwinger-Dyson iden
tities from various physical perspectives: in the context of the 3d gauge
theory itself\, in a 1d gauged quantum mechanics\, in 2d q-Toda theory\, a
nd in 6d little string theory. We establish the dictionary between all app
roaches.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joerg Teschner (DESY)
DTSTART:20201116T211000Z
DTEND:20201116T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/15
DESCRIPTION:Title: Proposal for a geometric characterisation of topological stri
ng partition functions\, part II\nby Joerg Teschner (DESY) as part of
Informal string-math seminar\n\n\nAbstract\nAbstract: In the second part o
f 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 follow
ing points:\n\nRelation to geometry of hypermultiplet moduli spaces\nRelat
ion to the spectrum of BPS-states\, geometry of space of stability conditi
ons\nRelation classical-quantum\nRelation with Theta-functions on intermed
iate Jacobian fibration\nInterplay between 2d-4d wall-crossing and free fe
rmion picture.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrew Manion (University of Southern California)
DTSTART:20201123T211000Z
DTEND:20201123T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/16
DESCRIPTION:Title: Higher representations and cornered Heegaard Floer homology\nby Andrew Manion (University of Southern California) as part of Inform
al string-math seminar\n\n\nAbstract\nStarting with some context and motiv
ation from a mathematical and physical perspective\, I will discuss recent
work with Raphael Rouquier on a higher tensor product operation for 2-rep
resentations of Khovanov's categorification of U(gl(1|1)^+)\, examples of
such 2-representations that arise as strands algebras in bordered and corn
ered Heegaard Floer homology\, and a tensor-product-based gluing formula f
or these 2-representations expanding on work of Douglas-Manolescu.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miroslav Rapcak (UC Berkeley)
DTSTART:20201130T211000Z
DTEND:20201130T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/17
DESCRIPTION:Title: Miura Operators\, Degenerate Fields and the M2-M5 Intersectio
n\nby Miroslav Rapcak (UC Berkeley) as part of Informal string-math se
minar\n\n\nAbstract\nStacks of M2-branes in Omega background lead to a cla
ss of Coulomb branch algebras due to Kodera and Nakajima. On the other han
d\, stacks of M5-branes in Omega background lead to a class of vertex oper
ator algebras due to a version of the AGT correspondence. I will provide a
new interpretation of key objects in the theory of vertex operator algebr
as\, such as Miura operators and degenerate fields\, as describing various
junctions of M2 and M5 branes in M-theory. The new perspective leads to a
rather close interplay between the relevant class of Coulomb branch algeb
ras and vertex operator algebras with many striking consequences.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nikita Nekrasov (Simons Center)
DTSTART:20210125T211000Z
DTEND:20210125T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/18
DESCRIPTION:Title: Beneath the surface: Knizhnik-Zamolodchikov equation in four
dimensions\nby Nikita Nekrasov (Simons Center) as part of Informal str
ing-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Davide Gaiotto (Perimeter Institute)
DTSTART:20210201T211000Z
DTEND:20210201T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/19
DESCRIPTION:Title: Vertex operators and screening charges as gauge-invariant bra
ne intersections in twisted M-theory\nby Davide Gaiotto (Perimeter Ins
titute) as part of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Benoit Vicedo (University of York)
DTSTART:20210208T211000Z
DTEND:20210208T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/20
DESCRIPTION:by Benoit Vicedo (University of York) as part of Informal stri
ng-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Horava (UC Berkeley)
DTSTART:20210222T211000Z
DTEND:20210222T224000Z
DTSTAMP:20260422T212527Z
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\nAbstr
act: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Brini (University of Sheffield)
DTSTART:20210301T211000Z
DTEND:20210301T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/22
DESCRIPTION:Title: Quantum geometry and physics of Looijenga pairs\nby Andre
a Brini (University of Sheffield) as part of Informal string-math seminar\
n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tobias Ekholm (Uppsala University)
DTSTART:20210308T211000Z
DTEND:20210308T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/23
DESCRIPTION:Title: Knot conormals\, quantum curves\, holomorphic disks\, and qui
vers\nby Tobias Ekholm (Uppsala University) as part of Informal string
-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivan Danilenko (UC Berkeley)
DTSTART:20210329T211000Z
DTEND:20210329T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/24
DESCRIPTION:Title: Quantum Cohomology and Slices of the Affine Grassmannian\
nby Ivan Danilenko (UC Berkeley) as part of Informal string-math seminar\n
\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vivek Shende (UC Berkeley)
DTSTART:20210315T201000Z
DTEND:20210315T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/25
DESCRIPTION:Title: Gluing the mirror\nby Vivek Shende (UC Berkeley) as part
of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hiraku Nakajima
DTSTART:20210405T211000Z
DTEND:20210405T224000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/26
DESCRIPTION:Title: Geometric Satake for affine Lie algebras\nby Hiraku Nakaj
ima as part of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mykola Dedushenko
DTSTART:20210503T201000Z
DTEND:20210503T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/28
DESCRIPTION:Title: Stable envelopes and Janus: a QFT home for some geometric con
structions\nby Mykola Dedushenko as part of Informal string-math semin
ar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Taro Kimura
DTSTART:20210510T201000Z
DTEND:20210510T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/29
DESCRIPTION:Title: Aspects of supergroup gauge theory\nby Taro Kimura as par
t of Informal string-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pavel Etingof
DTSTART:20210419T201000Z
DTEND:20210419T214000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/30
DESCRIPTION:by Pavel Etingof as part of Informal string-math seminar\n\nAb
stract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Peter Koroteev (UC Berkeley)
DTSTART:20211011T211000Z
DTEND:20211011T230000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/31
DESCRIPTION:Title: q-Opers\, QQ-Systems and Bethe Ansatz II\nby Peter Korote
ev (UC Berkeley) as part of Informal string-math seminar\n\n\nAbstract\nWe
introduce the notions of (G\,q)-opers and Miura (G\,q)-opers\, where G is
a simply-connected complex simple Lie group\, and prove some general resu
lts about their structure. We then establish a one-to-one correspondence b
etween the set of (G\,q)-opers of a certain kind and the set of nondegener
ate solutions of a system of Bethe Ansatz equations. Additionally we assoc
iate to a (G\,q)-oper a class of meromorphic sections of a G-bundle\, sati
sfying certain difference equations\, which we refer to as generalized q-W
ronskians. We show that the QQ-systems and their extensions emerge as the
relations between generalized minors\, thereby putting the Bethe Ansatz eq
uations in the framework of cluster mutations known in the theory of doubl
e Bruhat cells.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edward Witten (Institute for Advanced Study)
DTSTART:20211018T211000Z
DTEND:20211018T230000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/32
DESCRIPTION:Title: Complex Metrics in Spacetime\nby Edward Witten (Institute
for Advanced Study) as part of Informal string-math seminar\n\n\nAbstract
\nIn the ``Euclidean'' approach to quantum gravity\, it sometimes seems us
eful to include complex saddle points. But what class of complex spacetime
metrics is physically sensible? That will be the topic of this lecture.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ben Webster (Perimeter Institute)
DTSTART:20211025T211000Z
DTEND:20211025T230000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/33
DESCRIPTION:by Ben Webster (Perimeter Institute) as part of Informal strin
g-math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Richard Thomas (Imperial College\, London)
DTSTART:20211101T201000Z
DTEND:20211101T220000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/34
DESCRIPTION:Title: Nonabelian DT theory from abelian\nby Richard Thomas (Imp
erial College\, London) as part of Informal string-math seminar\n\n\nAbstr
act\nFix a Calabi-Yau 3-fold X. Its DT invariants count stable bundles and
sheaves on X. The generalised DT invariants of Joyce-Song count semistabl
e bundles and sheaves on X. I will describe work with Soheyla Feyzbakhsh s
howing these generalised DT invariants in any rank r can be written in ter
ms 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 D4-D2-D0
branes: rank 0 sheaves supported on surfaces in X. These invariants are p
redicted by S-duality to be governed by (vector-valued\, mock) modular for
ms.\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joerg Teschner (DESY)
DTSTART:20211108T201000Z
DTEND:20211108T220000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/35
DESCRIPTION:by Joerg Teschner (DESY) as part of Informal string-math semin
ar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ina Petkova (Dartmouth College)
DTSTART:20211115T223000Z
DTEND:20211116T003000Z
DTSTAMP:20260422T212527Z
UID:BerkeleyStringMathe/36
DESCRIPTION:by Ina Petkova (Dartmouth College) as part of Informal string-
math seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/BerkeleyStringMathe/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michele Del Zotto (University of Durham)
DTSTART:20211129T221000Z
DTEND:20211130T000000Z
DTSTAMP:20260422T212527Z
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://researchseminars.org/talk/BerkeleyStringMathe/37/
END:VEVENT
END:VCALENDAR