BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Roland Speicher (Saarbrucken)
DTSTART;VALUE=DATE-TIME:20200512T150000Z
DTEND;VALUE=DATE-TIME:20200512T160000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/1
DESCRIPTION:Title: Random matrices and their limits\nby Roland Speicher (Saar
brucken) as part of Wales MPPM Mathematical Physics\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Makoto Yamashita (Oslo)
DTSTART;VALUE=DATE-TIME:20200519T153000Z
DTEND;VALUE=DATE-TIME:20200519T163000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/2
DESCRIPTION:Title: Categorical quantization of symmetric spaces and reflection eq
uation\nby Makoto Yamashita (Oslo) as part of Wales MPPM Mathematical
Physics\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tobias Osborne (Hannover)
DTSTART;VALUE=DATE-TIME:20200526T153000Z
DTEND;VALUE=DATE-TIME:20200526T163000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/3
DESCRIPTION:Title: The search for a Haagerup CFT: a microscopic approach\nby
Tobias Osborne (Hannover) as part of Wales MPPM Mathematical Physics\n\nAb
stract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stefan Hollands (Leipzig)
DTSTART;VALUE=DATE-TIME:20200602T153000Z
DTEND;VALUE=DATE-TIME:20200602T163000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/4
DESCRIPTION:Title: State recovery\nby Stefan Hollands (Leipzig) as part of Wa
les MPPM Mathematical Physics\n\n\nAbstract\nPhysical operations on quantu
m states correspond to channels\, i.e. completely positive maps.\nSuch ope
rations are typically not invertible. Given that a state having gone throu
gh a channel cannot be completely recovered\, it is an important question
-- both theoretically but also\nfor practical purposes such as quantum err
or correction -- under what circumstances the state can perhaps be recover
ed with a high fidelity\, and how. As is well known\, channels may only re
duce the relative entropy between the given state and some reference state
\, a fact expressed by the famous "data processing inequality". In this ta
lk\, I present a strengthened version of this inequality for arbitrary ch
annels on v. Neumann algebras and explain how this inequality characterize
s the efficiency of state recovery.(Based on joint work with T. Faulkner.
)\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhengfeng Ji (UTS Sydney)
DTSTART;VALUE=DATE-TIME:20200609T100000Z
DTEND;VALUE=DATE-TIME:20200609T110000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/5
DESCRIPTION:Title: A complexity-theoretic solution to Connes' Embedding Problem\nby Zhengfeng Ji (UTS Sydney) as part of Wales MPPM Mathematical Physic
s\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ilijas Farah (York\, Ontario)
DTSTART;VALUE=DATE-TIME:20200616T153000Z
DTEND;VALUE=DATE-TIME:20200616T163000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/6
DESCRIPTION:Title: Recent applications of set theory to operator algebras\nby
Ilijas Farah (York\, Ontario) as part of Wales MPPM Mathematical Physics\
n\n\nAbstract\nCertain questions in the theory of operator algebras have b
een recently resolved using set theory. In this talk I’ll concentrate on
representation theory of simple C*-algebras and on the structure of the C
alkin algebra as well as the other coronas (i.e.\, outer multiplier algebr
as) of separable\, non-unital\, C*-algebras. No previous knowledge of set
theory or logic will be assumed.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gus Lehrer (Sydney U)
DTSTART;VALUE=DATE-TIME:20200623T090000Z
DTEND;VALUE=DATE-TIME:20200623T100000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/7
DESCRIPTION:Title: The second fundamental theorem of invariant theory for the ort
hosymplectic and periplectic groups\nby Gus Lehrer (Sydney U) as part
of Wales MPPM Mathematical Physics\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Constantin Teleman (Berkeley)
DTSTART;VALUE=DATE-TIME:20200630T153000Z
DTEND;VALUE=DATE-TIME:20200630T163000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/8
DESCRIPTION:Title: Go and No-Go in Chern-Simons theory\nby Constantin Teleman
(Berkeley) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nThe
3-dimensional Chern-Simons theory for a compact Lie group G is an intrigui
ng topological field theory which admits a distinguished 2D boundary theor
y\, the conformal WZW model. No topological boundary theories are known ex
cept in very special cases. (“Gapped” and “ungapped” are sometimes
used in lieu of conformal and topological.) Recently\, Dan Freed and myse
lf showed that\, in the setting of fully extended TQFTs\, no such boundary
theories can exist\, unless the Chern-Simons theory is equivalent to a c
ombinatorial state-sum theory (of Turaev-Viro type). After recalling that
“no-go” result\, I will outline its logical development into a “go
” theorem\, which constructs a universal target for Chern-Simons theorie
s (and more general Reshetikhin-Turaev ones) in which they are all generat
ed by an object attached to a point\, whose Drinfeld center is the relevan
t modular tensor category.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:James Tener (ANU\, Canberra)
DTSTART;VALUE=DATE-TIME:20200707T090000Z
DTEND;VALUE=DATE-TIME:20200707T100000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/9
DESCRIPTION:Title: Thin cobordisms and operator algebras in conformal field theor
y\nby James Tener (ANU\, Canberra) as part of Wales MPPM Mathematical
Physics\n\n\nAbstract\nThe mathematics of conformal field theory means dif
ferent things to different people. The three most common ways of studying
2d chiral conformal field theories are i) vertex aglebras\, ii) nets of op
erator algebras\, and iii) geometric field theories which assign invariant
s to complex cobordisms. In this talk I will present an extension of the n
otion of geometric field theory in which the Riemann `surfaces’ are allo
wed to have incoming and outgoing boundary overlap. I will also discuss ho
w these `surfaces’ give new realizations of nets of observables\, and ho
w these ideas have been applied to answer operator algebraic questions in
conformal field theory.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mike Hartglass (Santa Clara)
DTSTART;VALUE=DATE-TIME:20200714T153000Z
DTEND;VALUE=DATE-TIME:20200714T163000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/10
DESCRIPTION:Title: Realizations of Rigid C*-tensor categories as bimodules over
GJS C*-algebras\nby Mike Hartglass (Santa Clara) as part of Wales MPPM
Mathematical Physics\n\n\nAbstract\nGiven a countably generated rigid C*-
tensor category\, C\, I will construct a separable\, simple\, unital C*-al
gebra B with unique trace\, along with a fully faithful functor F from C i
nto the finitely-generated projective modules over B. This is joint work
with Roberto Hernandez Palomares.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ian Charlesworth (Berkeley)
DTSTART;VALUE=DATE-TIME:20200908T153000Z
DTEND;VALUE=DATE-TIME:20200908T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/11
DESCRIPTION:Title: Free Stein Dimension\nby Ian Charlesworth (Berkeley) as p
art of Wales MPPM Mathematical Physics\n\n\nAbstract\nRegularity questions
in free probability ask what can be learned about a tracial von Neumann a
lgebra from probabilistic-flavoured qualities of a set of generators. Broa
dly speaking there are two approaches -- one based in microstates\, one in
free derivations -- which with the failure of Connes Embedding are now kn
own to be distinct. The non-microstates approach is not obstructed by non-
embeddable variables\, but can be more difficult to work with for other re
asons. I will speak on recent work with Brent Nelson\, where we introduce
a quantity called the free Stein dimension\, which measures how readily de
rivations may be defined on a collection of variables. I will spend some t
ime placing it in the context of other non-microstates quantities\, and sk
etch a proof of the exciting fact that free Stein dimension is a *-algebra
invariant.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Barry Simon (Cal Tech)
DTSTART;VALUE=DATE-TIME:20200915T153000Z
DTEND;VALUE=DATE-TIME:20200915T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/12
DESCRIPTION:Title: The Tale of a Wrong Conjecture: Borg’s Theorem for Periodic
Jacobi Matrices on Trees\nby Barry Simon (Cal Tech) as part of Wales
MPPM Mathematical Physics\n\n\nAbstract\nI will begin by reviewing work on
removal of eigenvalue degeneracy and its relevance to gap splitting. I’
ll next discuss Borg’s theorem. I’ll then describe a framework for dis
cussing periodic Jacobi matrices on trees and possible versions of Borg’
s theorem and a recent note that there are counterexamples. Finally\, I’
ll discuss possible modified conjectures. This includes joint work with Ni
r Avni and Jonathan Breuer.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sergey Neshveyev (Oslo)
DTSTART;VALUE=DATE-TIME:20200922T153000Z
DTEND;VALUE=DATE-TIME:20200922T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/13
DESCRIPTION:Title: Dual cocycles and quantization of locally compact groups\
nby Sergey Neshveyev (Oslo) as part of Wales MPPM Mathematical Physics\n\n
\nAbstract\nAlthough the problem of quantization of Lie bialgebras in the
purely algebraic (formal) setting was solved in full generality in the 199
0s by Etingof and Kazhdan\, the list of noncompact Lie bialgebras admittin
g a quantization in the analytic (operator algebraic) setting is still qui
te short. In my talk I will review the history of the problem and its conn
ection to classification of group actions on von Neumann algebras. I will
then consider a particular class of semidirect products. The simplest exam
ple in this class is the ax+b group over the reals. An operator algebraic
quantum analogue of this group was defined by Baaj and Skandalis\, and as
an application of a general theory it is now possible to show that it is o
btained by the dual cocycle twisting from the von Neumann algebra of the a
x+b group. (Based on a joint work with Pierre Bieliavsky\, Victor Gayral
and Lars Tuset.)\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ezra Getzler (Northwestern)
DTSTART;VALUE=DATE-TIME:20200929T153000Z
DTEND;VALUE=DATE-TIME:20200929T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/14
DESCRIPTION:Title: Lie n-groupoids\nby Ezra Getzler (Northwestern) as part o
f Wales MPPM Mathematical Physics\n\n\nAbstract\nI’ll discuss the defini
tion and some examples of Banach Lie groupoids. This is joint work with Ka
i Behrend. The basic example is a generalization of the Lie group GL(A) of
invertible elements of a Banach algebra\, but for differential graded Ban
ach algebras\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jon Keating (Oxford)
DTSTART;VALUE=DATE-TIME:20201006T153000Z
DTEND;VALUE=DATE-TIME:20201006T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/15
DESCRIPTION:Title: Joint Moments of Characteristic Polynomials of Random Unitary
Matrices Abstact:\nby Jon Keating (Oxford) as part of Wales MPPM Mat
hematical Physics\n\n\nAbstract\nI will review what is known and not known
about the joint moments of the characteristic polynomials of random unita
ry matrices and their derivatives. I will then explain some recent results
which relate the joint moments to an interesting class of measures\, know
n as Hua-Pickrell measures. This leads to the proof of a conjecture\, due
to Chris Hughes in 2000\, concerning the asymptotics of the joint moments\
, as well as establishing a connection between the measures in question an
d one of the Painlevé equations. This is joint work with Theo Assiotis a
nd Jon Warren.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Inna Entova-Aizenbud (Ben Gurion)
DTSTART;VALUE=DATE-TIME:20201013T153000Z
DTEND;VALUE=DATE-TIME:20201013T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/16
DESCRIPTION:Title: Jacobson-Morozov Lemma for Lie superalgebras using semisimpli
fication\nby Inna Entova-Aizenbud (Ben Gurion) as part of Wales MPPM M
athematical Physics\n\n\nAbstract\nI will present a generalization of the
Jacobson-Morozov Lemma for quasi-reductive algebraic supergroups (respecti
vely\, Lie superalgebras)\, based on the idea of semisimplification of ten
sor categories\, which will be explained during the talk. This is a joint
project with V. Serganova.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Narutaka Ozawa (RIMS Kyoto)
DTSTART;VALUE=DATE-TIME:20201020T100000Z
DTEND;VALUE=DATE-TIME:20201020T120000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/17
DESCRIPTION:Title: An entropic proof of cutoff on Ramanujan graphs\nby Narut
aka Ozawa (RIMS Kyoto) as part of Wales MPPM Mathematical Physics\n\n\nAbs
tract\nIt is recently proved by Lubetzky and Peres that the simple random
walk on a Ramanujan graph exhibits a cutoff phenomenon\, that is to say\,
the total variation distance of the random walk distribution from the unif
orm distribution drops abruptly from near 1 to near 0. I will talk about a
very simple proof based on functional analysis and entropic consideration
.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lai-Sang Young (Courant NYU)
DTSTART;VALUE=DATE-TIME:20201027T163000Z
DTEND;VALUE=DATE-TIME:20201027T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/18
DESCRIPTION:Title: Observable events and typical trajectories in finite and inf
inite dimensional dynamical systems\nby Lai-Sang Young (Courant NYU) a
s part of Wales MPPM Mathematical Physics\n\n\nAbstract\nSome of the words
in the title are obviously subject to interpretation. For dynamical syste
ms on finite dimensional spaces\, one often equates observable events with
positive Lebesgue measure sets\, and invariant measures that reflect the
large-time behaviors of positive Lebesgue measure sets of initial conditio
ns are considered to be of special importance. I will begin by reviewing t
hese concepts for general dynamical systems\, describing a simple dynamica
l picture that one might hope to be true. Reality is a little messier\, bu
t a small amount of random noise will bring this picture about. In the sec
ond part of my talk I will consider infinite dimensional systems such as s
emi-flows arising from dissipative evolutionary PDEs\, and discuss the ext
ent to which the ideas above can be generalized to infinite \ndimensions\,
proposing a notion of ``typical solutions".\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theo Johnson-Freyd (Dalhousie and Perimeter)
DTSTART;VALUE=DATE-TIME:20201110T163000Z
DTEND;VALUE=DATE-TIME:20201110T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/19
DESCRIPTION:Title: Pseudounitary slightly degenerate braided fusion categories a
dmit minimal modular extensions\nby Theo Johnson-Freyd (Dalhousie and
Perimeter) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nA bra
ided fusion category is "slightly degenerate" if its Muger centre is a cop
y of SVec: they arise as the line operators of 3d spin-TFTs. It is a longs
tanding conjecture that any such braided fusion category admits a "minimal
modular extension"\, i.e. an index-2 extension to a nondegenerate braided
fusion category. I will outline a proof\, which is joint work in progress
with David Reutter\, of this conjecture in the pseudounitary case. The pr
oof involves traveling into four\, and briefly five\, dimensions.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cris Negron (U of North Carolina)
DTSTART;VALUE=DATE-TIME:20201117T163000Z
DTEND;VALUE=DATE-TIME:20201117T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/20
DESCRIPTION:Title: Quantum groups at even roots of unity and their corresponding
vertex algebras\nby Cris Negron (U of North Carolina) as part of Wale
s MPPM Mathematical Physics\n\n\nAbstract\nI will discuss quantum groups a
t even roots of unity and their corresponding logarithmic CFTs/VOAs. I wi
ll focus on quantum SL(2) and the triplet vertex operator algebra. Here t
here is a conjectured (ribbon tensor) equivalence between the category of
representations for small quantum SL(2)\, and the category of representati
ons for the triplet algebra. In the talk I will explain how certain pheno
mena on the VOA side of this conjecture are mirrored on the quantum group
side\, and how such mirrored phenomena might inform how we approach the co
njectured equivalence\, and related equivalences in ``higher rank".\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Meyer (Gottingen)
DTSTART;VALUE=DATE-TIME:20201201T163000Z
DTEND;VALUE=DATE-TIME:20201201T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/21
DESCRIPTION:Title: Coarse geometry and topological insulators\nby Ralf Meyer
(Gottingen) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nI e
xplain that topological materials with no restriction on disorder may be m
odelled by the Roe C*-algebra of the Euclidean space of appropriate dimens
ion. The K-theory of this observable algebra gives exactly the strong top
ological phases. In this picture\, the bulk-boundary correspondence is re
lated to the coarse Mayer-Vietoris sequence. Explicit formulas for the bo
undary map in van Daele's K-theory will be deduced from the naturality of
the boundary map. In the end\, I would like to discuss how the descriptio
n of strong topological phases could be extended to interacting field theo
ries. Here the description through the Roe C*-algebra indicates a possibl
e way. Namely\, the position observables already generate the Hilbert spa
ce representation of the Roe C*-algebra. A Hamiltonian gives a class in t
he K-theory of the Roe C*-algebra provided it has a spectral gap\, is loca
lly compact\, and norm-continuous for the R^d-action generated by the posi
tion observables.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philippe Di Francesco (U of Illinois At Urbana-Champaign and IPhT
Saclay)
DTSTART;VALUE=DATE-TIME:20201124T163000Z
DTEND;VALUE=DATE-TIME:20201124T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/22
DESCRIPTION:Title: Triangular Ice: Combinatorics and Limit Shapes\nby Philip
pe Di Francesco (U of Illinois At Urbana-Champaign and IPhT Saclay) as par
t of Wales MPPM Mathematical Physics\n\n\nAbstract\nWe consider the triang
ular lattice version of the two-dimensional ice model with suitable bounda
ry conditions\, leading to an integrable 20 Vertex model. Configurations g
ive rise to generalizations of Alternating Sign Matrices\, which we call A
lternating Phase Matrices (APM). After reviewing a few facts on the square
lattice version and the role of integrability\, we compute the number of
APM of any given size in the form of a determinant\, which turns out to ma
tch the number of quarter-turn symmetric domino tilings of a quasi-Aztec s
quare with a central cross-shaped hole. We also present conjectures for tr
iangular Ice with other types of boundary conditions\, and results on the
limit shape of large APM\, obtained by applying the so-called "Tangent Met
hod".\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Richard Thomas (Imperial)
DTSTART;VALUE=DATE-TIME:20201103T163000Z
DTEND;VALUE=DATE-TIME:20201103T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/23
DESCRIPTION:Title: Counting sheaves on Calabi-Yau 4-folds\nby Richard Thomas
(Imperial) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nI wi
ll outline\, in a down-to-earth way\, how invariants are extracted from mo
duli spaces in modern enumerative algebraic geometry. The key tool is some
thing called a “virtual cycle”\, which can be understood as some kind
of “localised Euler class”. We will see this works for 3 complex dimen
sional Calabi-Yau manifolds\, but not for 4-folds. Then I will explain a f
ix using “localised square root Euler classes for special orthogonal bun
dles”. Joint work with Jeongseok Oh (KIAS).\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chris Bourne (Tohoku U)
DTSTART;VALUE=DATE-TIME:20201208T110000Z
DTEND;VALUE=DATE-TIME:20201208T130000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/24
DESCRIPTION:Title: Gapped ground states and symmetry protected topological (SPT)
phases of infinite fermion chains\nby Chris Bourne (Tohoku U) as part
of Wales MPPM Mathematical Physics\n\n\nAbstract\nGapped ground states ha
ve attracted much interest from physicists and mathematicians as a means t
o characterise physical effects that are described by topological invarian
ts and therefore stable under small perturbations. In this talk I will rev
iew the analytic/operator algebraic approach to gapped ground states\, whi
ch allows us to work in the thermodynamic limit directly. I will then show
how the split property allows us to define topological indices to pure ga
pped 1D ground states with an on-site finite group symmetry. Time permitti
ng\, I will also compare to other methods to study SPT phases such as tens
or networks and (invertible) TQFT. This is joint work with Yoshiko Ogata (
Univ. Tokyo)\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Feng Xu (UC Riverside)
DTSTART;VALUE=DATE-TIME:20201215T163000Z
DTEND;VALUE=DATE-TIME:20201215T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/25
DESCRIPTION:Title: Rigorous results about relative entropy in QFT\nby Feng
Xu (UC Riverside) as part of Wales MPPM Mathematical Physics\n\n\nAbstract
\nWe will present some rigorous results about relative entropy in QFT\, m
otivated in part by recent physicists work which however depends on heuri
stic arguments such as introducing cut off and using path integrals. In th
e particular case of CFT\, we will discuss interesting relations between r
elative entropy\, central charge and global dimension of conformal net.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claudia Scheimbauer (TU Munich)
DTSTART;VALUE=DATE-TIME:20210126T163000Z
DTEND;VALUE=DATE-TIME:20210126T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/26
DESCRIPTION:Title: The AKSZ construction as a fully extended topological field t
heory\nby Claudia Scheimbauer (TU Munich) as part of Wales MPPM Mathem
atical Physics\n\n\nAbstract\nClassical Poincaré-Lefschetz duality is a s
tarting point of understanding what an orientation on a derived stack give
n by a homotopy type of a cobordism M is. If furthermore we have an (n-)sy
mplectic "target" X\, we obtain a (shifted) symplectic on Map(M\,X) which
is given by pulling back along an evaluation and then integrating. This ex
plains the Atiyah-Bott symplectic form on G-local systems\, arising from t
he Killing form on the Lie algebra of a reductive group G\, via derived s
ymplectic geometry in the sense of Pantev-Toen-Vaquié-Vezzosi. In this ta
lk I will sketch these ideas and explain how this leads to a fully extende
d oriented topological field theory with values in a suitable higher categ
ory of Lagrangians\, explaining the difficulties with coherence in definin
g such a functor. In essence\, the difficulty with coherence stems from in
tegration of differential forms not being functorial for cobordisms on the
nose\, but only up to homotopy. In mathematical physics\, this TFT is a r
einterpretation/analog of the classical AKSZ construction for certain $\\s
igma$-models and describes "semi-classical TFTs”. This is joint work wit
h Damien Calaque and Rune Haugseng and fully extends a construction by the
former.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivan Cherednik (U North Carolina\, Chapel Hill)
DTSTART;VALUE=DATE-TIME:20210202T163000Z
DTEND;VALUE=DATE-TIME:20210202T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/27
DESCRIPTION:Title: Riemann hypothesis for plane curve singularities\nby Ivan
Cherednik (U North Carolina\, Chapel Hill) as part of Wales MPPM Mathemat
ical Physics\n\n\nAbstract\nWe will begin with a mini-review of the classi
cal theories of\nzeta-functions\, and then switch to the zeta and L-functi
ons\nof plane curve singularities\, conjecturally coinciding with the\nmot
ivic super-polynomials\, defined in terms of compactified\nJacobians of th
ese singularities. The focus is on the functional\nequation\, matching the
DAHA super-duality and\, presumably\,\nthe physics S-duality in M-theory.
DAHA provides here powerful\noperator methods\, closely related to refine
d Verlinde algebras.\nWe will calculate the DAHA super-polynomial and the
motivic\none for trefoil. Generally\, they are expected to coincide with\n
the stable Khovanov-Rozansky polynomials of algebraic knots.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrew Schopieray (PIMS)
DTSTART;VALUE=DATE-TIME:20210209T163000Z
DTEND;VALUE=DATE-TIME:20210209T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/28
DESCRIPTION:Title: Number fields and the quantum subgroup problem\nby Andrew
Schopieray (PIMS) as part of Wales MPPM Mathematical Physics\n\n\nAbstrac
t\nThere was a long-standing conjecture that\, stated very loosely\, there
exist finitely-many exceptional quantum subgroups for each of the affine
Lie algebras. This conjecture can be understood as a question about commu
tative algebra objects in modular tensor categories. It was announced a f
ew years ago that this conjecture shall become a theorem\, the proof of wh
ich relies on number-theoretic aspects of modular tensor categories includ
ing the Galois symmetry of modular data. In this talk\, I will discuss bo
th results and future directions of research that have arisen from my own
contributions to resolving this conjecture\, including Witt group relation
s\, non-pseudounitary fusion rules\, and minimal modular closure conjectur
es.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bin Gui (Rutgers)
DTSTART;VALUE=DATE-TIME:20210216T163000Z
DTEND;VALUE=DATE-TIME:20210216T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/29
DESCRIPTION:Title: Categorical extensions of conformal nets\nby Bin Gui (Rut
gers) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nWightman Q
FT and Haag-Kastler QFT are two major mathematically rigorous axiomatizati
ons of quantum field theory. For 2d chiral conformal field theory\, these
two are respectively the vertex operator algebra approach (describing the
chiral fields) and the conformal net approach (describing bounded observab
les on the circle). To construct and understand full and boundary CFT\, an
d to investigate the representation tensor categories for chiral CFT\, one
also needs charged fields (known as intertwining operators or conformal b
locks in the literature of vertex algebras) which map between different re
presentations of the chiral fields. In this talk\, I will introduce catego
rical extensions of conformal nets as a Haag-Kastler theory for charged fi
elds. I will argue that this approach provides a natural framework of desc
ribing the locality property for charged fields. I will use Connes fusion
(Connes relative tensor product) to motivate the definition.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mayuko Yamashita (RIMS Kyoto)
DTSTART;VALUE=DATE-TIME:20210223T110000Z
DTEND;VALUE=DATE-TIME:20210223T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/30
DESCRIPTION:Title: The classification problem of non-topological invertible QFT
’s and a “physicists-friendly” model for the Anderson duals\nby
Mayuko Yamashita (RIMS Kyoto) as part of Wales MPPM Mathematical Physics\n
\n\nAbstract\nFreed and Hopkins conjectured that the deformation classes o
f non-topological invertible quantum field theories are classified by a ge
neralized cohomology theory called the Anderson dual of bordism theories.
The main difficulty of this problem lies in the fact that we do not have t
he axioms for QFT’s. In this talk\, I will explain the ongoing work to g
ive a new approach tothis conjecture. We construct a new\, “physicists-f
riendly” model for the Anderson duals.This model is constructed so that
it abstracts a certain property of invertible QFT’s which physicists bel
ieve to hold in general. I will start from basic motivations for the class
ification problem\, report the progress of our work and explain future dir
ections. This is the joint work with Yosuke Morita (Kyoto\, math) and Kazu
ya Yonekura (Kyushu\, physics).\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nilanjana Datta (DAMTP Cambrdige)
DTSTART;VALUE=DATE-TIME:20210302T163000Z
DTEND;VALUE=DATE-TIME:20210302T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/31
DESCRIPTION:Title: Perfect discrimination of unitary channels and novel quantum
speed limits\nby Nilanjana Datta (DAMTP Cambrdige) as part of Wales MP
PM Mathematical Physics\n\n\nAbstract\nDiscriminating between unknown obje
cts in a given set is a fundamental task in experimental science. Suppose
you are given a quantum system which is in one of two given states with eq
ual probability. Determining the actual state of the system amounts to doi
ng a measurement on it which would allow you to discriminate between the t
wo possible states. It is known that unless the two states are mutually or
thogonal\, perfect discrimination is possible only if you are given arbitr
arily many identical copies of the state.\n\nIn this talk we consider the
task of discriminating between quantum channels\, instead of quantum state
s. In particular\, we discriminate between a pair of unitary channels acti
ng on a quantum system whose underlying Hilbert space is infinite-dimensio
nal. We prove that in contrast to state discrimination\, one only needs a
finite number of uses of these channels in order to discriminate perfectly
between them. Furthermore\, no entanglement is needed in the discriminati
on task. The measure of discrimination is given in terms of the energy-con
strained diamond norm\, and a key ingredient of the proofs of these result
s is a generalization of the Toeplitz-Hausdorff Theorem of convex analysis
. Moreover\, we employ our results to study a novel type of quantum speed
limits which apply to pairs of quantum evolutions. This work was done joi
ntly with Simon Becker (Cambridge)\, Ludovico Lami (Ulm) and Cambyse Rouze
(Munich).\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reinhard Werner (ReinLeibniz Universität\, Hannover)
DTSTART;VALUE=DATE-TIME:20210309T163000Z
DTEND;VALUE=DATE-TIME:20210309T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/32
DESCRIPTION:Title: Topological classification of spin chains and quantum walks\nby Reinhard Werner (ReinLeibniz Universität\, Hannover) as part of Wa
les MPPM Mathematical Physics\n\n\nAbstract\nI will consider two types of
one-dimensional discrete time lattice systems: On the one hand\, there are
spin chains\, infinite tensor products of finite quantum systems. With a
discrete time evolution automorphism\, they are called quantum cellular au
tomata (QCAs). On the other\, there are quantum walks\, direct sums of fin
ite quantum systems\, whose one-step dynamics is given by a unitary operat
or. In both cases\, the discreteness of time leads to an interesting inter
play between unitarity and locality\, which is absent in the continuous ti
me (Hamiltonian) analogues. It is measured by an index\, which assumes rat
ional values in the QCA case and integers in the walk case. I will illustr
ate it by the index theorem for juggling patterns (these are special walks
) and the memory invariant for reversible qubit-stream processors (special
QCAs). The geometric features of the lattice are encoded in a "coarse str
ucture"\, which will be important for analogues of this theory in higher d
imensions. But even in the translation invariant one-dimensional case ther
e are different choices\, which I will briefly describe.\n\nI will then co
nsider quantum walks with discrete symmetries and a spectral gap condition
. No translation invariance and only approximate locality are assumed. In
the Hamiltonian case this leads to the so-called tenfold way\, of which I
will give a characterization justifying the number ten. In the unitary cas
e\, the same assumptions once again lead to more possibilities. Topologica
l classification is in terms of an index group\, and requires three indice
s: one for the asymptotic behaviour on the left\, one on the right\, and o
ne to classify non-gentle perturbations\, i.e.\, local modifications of th
e walk that cannot be deformed away.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cain Edie-Mitchell (Vanderbilt University)
DTSTART;VALUE=DATE-TIME:20210316T163000Z
DTEND;VALUE=DATE-TIME:20210316T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/33
DESCRIPTION:Title: Type II quantum subgroups for sl_n\nby Cain Edie-Mitchell
(Vanderbilt University) as part of Wales MPPM Mathematical Physics\n\n\nA
bstract\nQuantum subgroups are module categories\, which encode the ``high
er representation theory'' of the Lie algebras. They appear naturally in m
athematical physics\, where they correspond to extensions of the Wess-Zumi
no-Witten models. The classification of these quantum subgroups has been a
long-standing open problem. The main issue at hand being the possible exi
stence of exceptional examples. Despite considerable attention from both p
hysicists and mathematicians\, full results are only known for sl_2 and sl
_3.\n \nIn this talk I will discuss recent progress in the classification
of type II quantum subgroups for sl_n. Our results finish off the classifi
cation for n = 4\,5\,6\,7\, and pave the way for higher ranks. In particul
ar we discover several exceptional examples.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhengwei Liu (Tsinghua University\, Beijing)
DTSTART;VALUE=DATE-TIME:20210323T163000Z
DTEND;VALUE=DATE-TIME:20210323T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/34
DESCRIPTION:Title: Quantum Fourier Analysis\nby Zhengwei Liu (Tsinghua Unive
rsity\, Beijing) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\
nQuantum Fourier Analysis is a subject that combines an algebraic Fourier
transform (pictorial in the case of subfactor theory) with analytic estima
tes. This provides interesting tools to investigate phenomena such as quan
tum symmetry. In this talk\, we will introduce its background\, developmen
t and perspectives\, based on selected examples\, results and applications
.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yoshiko Ogata (Tokyo U)
DTSTART;VALUE=DATE-TIME:20210420T100000Z
DTEND;VALUE=DATE-TIME:20210420T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/35
DESCRIPTION:Title: Classification of gapped ground state phases in quantum spin
systems\nby Yoshiko Ogata (Tokyo U) as part of Wales MPPM Mathematical
Physics\n\n\nAbstract\nI would like to explain about classification of ga
pped ground state\nphases in quantum spin systems\, in the operator algebr
aic framework of quantum statistical mechanics.The talk consists of two pa
rts. The first part is about classification problem of so called SPT (symm
etry protected topological) phases. We see that it is classified by group
cohomology\, in one and two dimension.In the second part (joint work with
Pieter Naaijkens)\, we see that superselection sector is a topological inv
ariant.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emily Riehl (Johns Hopkins)
DTSTART;VALUE=DATE-TIME:20210427T153000Z
DTEND;VALUE=DATE-TIME:20210427T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/36
DESCRIPTION:Title: Elements of ∞-Category Theory\nby Emily Riehl (Johns Ho
pkins) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nConfusing
ly for the uninitiated\, experts in weak infinite-dimensional category the
ory make use of different definitions of an ∞-category\, and theorems in
the ∞-categorical literature are often proven "analytically"\, in refer
ence to the combinatorial specifications of a particular model. In this ta
lk\, we present a new point of view on the foundations of ∞-category the
ory\, which allows us to develop the basic theory of ∞-categories - adju
nctions\, limits and colimits\, co/cartesian fibrations\, and pointwise Ka
n extensions - "synthetically" starting from axioms that describe an ∞-c
osmos\, the infinite-dimensional category in which ∞-categories live as
objects. We demonstrate that the theorems proven in this manner are "model
-independent"\, i.e.\, invariant under change of model. Moreover\, there i
s a formal language with the feature that any statement about ∞-categori
es that is expressible in that language is also invariant under change of
model\, regardless of whether it is proven through synthetic or analytic t
echniques. This is joint work with Dominic Verity.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuki Arano (Kyoto University)
DTSTART;VALUE=DATE-TIME:20210504T100000Z
DTEND;VALUE=DATE-TIME:20210504T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/37
DESCRIPTION:Title: Ergodic theory of affine isometric actions on Hilbert spaces<
/a>\nby Yuki Arano (Kyoto University) as part of Wales MPPM Mathematical P
hysics\n\n\nAbstract\nI introduce nonsingular actions of groups on probabi
lity spaces constructed from affine isometric actions on Hilbert spaces\,
which we call the non-singular Gausian action. Then I discuss the ergodici
ty and the type determination for groups acting on trees.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Rosenberg (U of Maryland)
DTSTART;VALUE=DATE-TIME:20210511T153000Z
DTEND;VALUE=DATE-TIME:20210511T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/39
DESCRIPTION:Title: Gap Labeling and the Noncommutative Bloch Theorem\nby Jon
athan Rosenberg (U of Maryland) as part of Wales MPPM Mathematical Physics
\n\n\nAbstract\nNoncommutative geometry provides powerful mathematical too
ls for studying thephysical properties of non-periodic but still somewhat
regular solids. Such materials\, often called “quasi-crystals”\, do o
ccur in nature and are based on non-periodic tilings. (These were recogni
zed in Schechtman’s 2011 Nobel Prize.) Attempts to predict the Bragg pea
ks and spectral properties of such materials led to a program pioneered by
Jean Bellissardand pursued by many others\, of studying “gap labeling
”\, predicting spectral gaps based on thedynamics of the tiling. This i
s closely related to the Čech cohomology of the “tiling space” andthe
K-theory of a certain C*-algebra associated to the tiling. We explain ho
w this comes about\,how various people gave false proofs of the “Gap Lab
eling Conjecture”\, and how to obtain somenew results. This is joint wo
rk with Claude Schochet\, Eric Akkermans\, and Yaroslav Don.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Johannes Kellendonk (JohanneUniversité Claude Bernard Lyon 1)
DTSTART;VALUE=DATE-TIME:20210525T153000Z
DTEND;VALUE=DATE-TIME:20210525T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/40
DESCRIPTION:Title: Bragg spectrum and gap-labelling\, a topological approach
\nby Johannes Kellendonk (JohanneUniversité Claude Bernard Lyon 1) as par
t of Wales MPPM Mathematical Physics\n\n\nAbstract\nA classical result in
solid state physics tells us that the gaps in the electronic spectrum of a
one dimensional crystal are located at those values for the quasi momentu
m k which belong to the Bragg spectrum of the crystal. The result is prove
n by perturbation theory. If one labels a gap with the integrated density
of states of energies up to that gap one obtains an order preserving map f
rom the positive Bragg spectrum to the set of gap labels. \nThe purpose of
the talk is to explain a similar map for aperiodic solids which is based
on methods from non-commutative topology\, namely we discuss an order pres
erving homomorphism between the group of topological Bragg peaks and the g
ap labelling group. \nA comparison with work by theoretical physicists fro
m the late ‘80s\, which is based on a perturbation expansion of the trac
e map for hierarchical systems\, finds disagreement. Not all gaps predicte
d by these perturbative expansions are there. $K$-theory provides selectio
n rules on the opening of gaps.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Buican (Queen Mary\, London)
DTSTART;VALUE=DATE-TIME:20210601T153000Z
DTEND;VALUE=DATE-TIME:20210601T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/41
DESCRIPTION:Title: aXb=c in 2+1D TQFT\nby Matthew Buican (Queen Mary\, Londo
n) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nI will discus
s fusion rules of the form aXb=c in 2+1D topological quantum field theorie
s. Here a\, b\, and c are simple objects of the associated modular tensor
categories (MTC). As I will explain\, when a and b have categorical dimens
ion larger than one\, such fusion rules imply interesting global constrain
ts on the MTC. The simplest possibility is that the MTC factorizes\, but t
here are other\, more interesting\, possibilities as well. Some of these l
atter possibilities may potentially be relevant for understanding various
problems in mathematical physics that I will describe.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arnaud Brothier (UNSW\, Sydney)
DTSTART;VALUE=DATE-TIME:20210928T100000Z
DTEND;VALUE=DATE-TIME:20210928T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/42
DESCRIPTION:Title: Jones' actions: from conformal field theory to Richard Thomps
on’s group\nby Arnaud Brothier (UNSW\, Sydney) as part of Wales MPPM
Mathematical Physics\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Victor Ostrik (Eugene\, Oregon)
DTSTART;VALUE=DATE-TIME:20211005T153000Z
DTEND;VALUE=DATE-TIME:20211005T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/43
DESCRIPTION:Title: Two dimensional topological field theories and partial fracti
ons\nby Victor Ostrik (Eugene\, Oregon) as part of Wales MPPM Mathemat
ical Physics\n\nAbstract: TBA\n\nbased on joint work with M. Khovanov and
Y. Kononov. By evaluating a topological field theory in dimension 2 on sur
faces of genus 0\,1\,2 etc we get a sequence. We investigate which sequenc
es occur in this way depending on the assumptions on the target category.\
n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ehud Meir (Aberdeen)
DTSTART;VALUE=DATE-TIME:20211012T153000Z
DTEND;VALUE=DATE-TIME:20211012T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/44
DESCRIPTION:Title: Interpolations of monoidal categories by invariant theory
\nby Ehud Meir (Aberdeen) as part of Wales MPPM Mathematical Physics\n\n\n
Abstract\nIn this talk I will consider algebraic structures such as lie\,
Hopf\, and Frobenius algebras. \nI will show that under certain assumption
s such structures can be reconstructed from the scalar invariants they def
ine. I will then show how one can interpolate the category of representati
on of the automorphism groups of the structures by interpolation the invar
iants of the algebraic structures. In this way we recover the construction
s of Deligne for categories such as Rep(S_t)\, Rep(O_t) and Rep(Sp_t)\, th
e constructions of Knop for\nwreath products with S_t\, and GL_t(O_r)\, wh
ere O_r is a finite quotient\nof a discrete valuation ring. We will also s
how how the TQFT categories recently\nconstructed from a rational function
by Khovanov\, Ostrik\, and Kononov arise in this context.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Semeon Artamonov (CRM\, Montreal)
DTSTART;VALUE=DATE-TIME:20211019T153000Z
DTEND;VALUE=DATE-TIME:20211019T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/45
DESCRIPTION:Title: Genus two Double Affine Hecke Algebra and its classical limit
\nby Semeon Artamonov (CRM\, Montreal) as part of Wales MPPM Mathemati
cal Physics\n\n\nAbstract\nWith every surface and reductive group G one ca
n associate G-character variety of its fundamental group. When the surface
is oriented\, the coordinate ring of G-character variety comes equipped w
ith the Goldman Poisson bracket. The quantization of this Poisson algebra
is known as G-skein algebra.\n\nIt is known that G-skein algebra of a toru
s admits flat one-parameter deformation into spherical subalgebra of Doubl
e Affine Hecke Alegrba (sDAHA). In my talk I will define a genus two analo
gue of sDAHA for G=SL(2). I will talk about finite-dimensional representat
ions of this algebra\, relation to TQFT\, classical limit\, and genus two
analogue of Macdonald polynomials.\n\nThis talk is based on joint work wit
h Sh.Shakirov.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sergei Gukov (Caltech & DIAS\, Dublin)
DTSTART;VALUE=DATE-TIME:20211026T153000Z
DTEND;VALUE=DATE-TIME:20211026T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/46
DESCRIPTION:Title: MTCs and TQFTs from 3d Coulomb branches\nby Sergei Gukov
(Caltech & DIAS\, Dublin) as part of Wales MPPM Mathematical Physics\n\nAb
stract: TBA\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adrian Ioana (UCSD)
DTSTART;VALUE=DATE-TIME:20211102T163000Z
DTEND;VALUE=DATE-TIME:20211102T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/47
DESCRIPTION:Title: Almost commuting matrices and stability for product groups\nby Adrian Ioana (UCSD) as part of Wales MPPM Mathematical Physics\n\n\n
Abstract\nI will present a result showing that the direct product group $G
=\\mathbb F_2\\times\\mathbb F_2$ is not Hilbert-Schmidt stable. This mean
s that G admits a sequence of asymptotic homomorphisms (with respect to th
e normalized Hilbert-Schmidt norm) which are not perturbations of genuine
homomorphisms. While this result concerns unitary matrices\, its proof re
lies on techniques and ideas from the theory of von Neumann algebras. I wi
ll also explain how this result can be used to settle in the negative a na
tural version of an old question of Rosenthal concerning almost commuting
matrices. More precisely\, we derive the existence of contraction matrices
A\,B such that A almost commutes with B and B* (in the normalized Hilbert
-Schmidt norm)\, but there are no matrices A’\,B’ close to A\,B such t
hat A’ commutes with B’ and B’*.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Colleen Delaney (Indiana U\, Bloomington)
DTSTART;VALUE=DATE-TIME:20211109T163000Z
DTEND;VALUE=DATE-TIME:20211109T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/48
DESCRIPTION:Title: Zesting and Witten-Reshetikhin-Turaev invariants\nby Coll
een Delaney (Indiana U\, Bloomington) as part of Wales MPPM Mathematical P
hysics\n\n\nAbstract\nI’ll discuss the ribbon zesting construction on pr
e-modular categories from a diagrammatic point of view and show that Witte
n-Reshetekhin-Turaev invariants of framed knots and links decouple under z
esting. As an application I will explain how the Mignard-Schauenburg ``mod
ular isotopes” can be understood through zesting.\n\nThis talk is based
on joint work with Cesar Galindo\, Julia Plavnik\, Eric Rowell\, and Qing
Zhang as well as Sung Kim.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Moritz Weber (Saarland)
DTSTART;VALUE=DATE-TIME:20211123T163000Z
DTEND;VALUE=DATE-TIME:20211123T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/49
DESCRIPTION:Title: Easy quantum groups and quantum permutations\nby Moritz W
eber (Saarland) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\n
Within Woronowicz’s framework of compact quantum groups\, there are natu
ral quantum analogs of the symmetric group\, the orthogonal group and the
unitary group\, amongst others. They have in common that their representat
ion theory may be expressed in terms of diagrams. This has been systematic
ally formalized by Banica and Speicher in 2009 within the class of so call
ed „easy“ quantum groups. We give an introduction to „easy“ quantu
m groups\, their diagrammatic representation theory and we mention some li
nks with Deligne’s interpolation categories. Moreover\, we highlight the
role of quantum permutations within the theory of quantum automorphism gr
oups of graphs. This also links with nonlocal games in quantum information
theory\, as we will point out.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jacob Bridgeman (Perimeter)
DTSTART;VALUE=DATE-TIME:20211130T163000Z
DTEND;VALUE=DATE-TIME:20211130T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/50
DESCRIPTION:Title: Enriched topological codes\nby Jacob Bridgeman (Perimeter
) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nTopological ph
ases are a promising substrate for quantum computing due to their inherent
error resistance. Unfortunately\, there seems to be a tradeoff between ho
w easily the codes can be realized in the lab\, and whether a universal se
t of gates can be implemented. Including defects into the code can be used
to boost the gateset. We use tube algebras to understand the properties o
f defects\, and hopefully which gates can be implemented.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gwyn Bellamy (Glasgow)
DTSTART;VALUE=DATE-TIME:20211207T163000Z
DTEND;VALUE=DATE-TIME:20211207T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/51
DESCRIPTION:Title: Invariant holonomic systems for symmetric spaces\nby Gwyn
Bellamy (Glasgow) as part of Wales MPPM Mathematical Physics\n\n\nAbstrac
t\nIf G is a reductive (connected\, complex) Lie group with Lie algebra g\
, then Hotta-Kashiwara introduced a certain D-module HC on g called the Ha
rish-Chandra D-module. This is precisely the module whose distributional s
olutions are the invariant eigen-distributions appearing in character theo
ry for real reductive Lie groups. A key result by Hotta-Kashiwara is that
HC is semi-simple with simple summands in bijection with the irreducible r
epresentations of the Weyl group (the algebraic Springer correspondence).
In this talk I'll describe a natural generalization of HC to a D-module on
the tangent space of a symmetric space. I'll explain the extent to which
Hotta-Kashiwara's results generalise to this setting. This is based on joi
nt work with Levasseur\, Nevins and Stafford\; I won't assume any prior kn
owledge of D-modules.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:George Willis (Newcastle\, NSW)
DTSTART;VALUE=DATE-TIME:20211116T110000Z
DTEND;VALUE=DATE-TIME:20211116T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/52
DESCRIPTION:Title: Flat groups of automorphisms of totally disconnected locally
compact groups.\nby George Willis (Newcastle\, NSW) as part of Wales M
PPM Mathematical Physics\n\n\nAbstract\nFlat groups of automorphisms are f
eatures of the structure of totally disconnected locally compact (t.d.l.c.
) groups that roughly correspond to Cartan subgroups in Lie and algebraic
groups. \nThe group $\\mathcal{H}$ of automorphisms of the t.d.l.c. group
$G$ is flat if there is $U\\leq G$ that is minimising for every $\\alpha\\
in\\mathcal{H}$\, and a compact open subgroup $U$ of $G$ is \\emph{minimis
ing} for $\\alpha$ if the index $[\\alpha(U) : \\alpha(U)\\cap U]$ is the
minimum as $U$ ranges over all compact open subgroups of $G$. \n\nThe stru
cture of flat groups and the associated minimising subgroups can be descri
bed in some detail and the first part of the talk will summarise this desc
ription. A couple of applications will then be outlined. The last part of
the talk will describe work in progress that strengthens the correspondenc
e with Lie algebra significantly and increases the scope of the structure
theorems.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claus Koestler (Cork)
DTSTART;VALUE=DATE-TIME:20220201T163000Z
DTEND;VALUE=DATE-TIME:20220201T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/53
DESCRIPTION:Title: Spreadability and Partial Spreadability\nby Claus Koestle
r (Cork) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nDistrib
utional symmetries and invariance principles provide deep structural resul
ts in classical probability\, also known as de Finetti theorems. I will in
troduce to some recent developments in the transfer of these principles to
noncommutative probability. \n\nFirst\, I will discuss spreadability of a
n infinite sequence of noncommutative random variables. This property is a
bout the invariance of distributions when passing from the given sequence
to a subsequence. It may be regarded to be the fundamental distributional
invariance principle from the viewpoint of algebraic homology as it emerg
es via a functor from the semisimplicial category into a category of nonco
mmutative probability spaces. \n\nFurthermore\, my talk will address part
ial spreadability\, a recently introduced generalization of spreadability.
This invariance principle provides a connection between certain represen
tations of the Thompson monoid $F^+$ and Markovianity in noncommutative p
robability.\n\nFinally\, as time permits\, I will address some open proble
ms when applying these two invariance principles to Jones-Temperley-Lieb a
lgebras. \n\nThis talk is based on joint work with Gwion Evans\, Rolf Goh
m\, Arundhathi Krishnan and Steven Wills. \n\n\nReferences:\n\nD. Gwion
Evans\, Rolf Gohm\, Claus Köstler. Semi-cosimplicial objects and spreada
bility. Rocky Mountain J. Math. 47 (6) 1839 - 1873\, 2017.\n\nClaus Köst
ler\, Arundhathi Krishnan\, Stephen J. Wills. Markovianity and the Thomps
on Monoid $F^+$\, arXiv:2009.14811.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Guoliang Yu (Texas A&M)
DTSTART;VALUE=DATE-TIME:20220208T163000Z
DTEND;VALUE=DATE-TIME:20220208T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/54
DESCRIPTION:Title: A new index theory for noncompact manifolds and Gromov's comp
actness conjecture\nby Guoliang Yu (Texas A&M) as part of Wales MPPM M
athematical Physics\n\n\nAbstract\nI will introduce a new index theory for
noncompact manifolds based on my joint work with Stanley Chang and Shmuel
Weinberger. This index theory encodes dynamics of the fundamental groups
at infinity. I will then discuss my recent work with Shmuel Weinberger and
Zhizhang Xie answering Gromov's compactness question on scalar curvature
using this index theory.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jesse Peterson (Vanderbilt)
DTSTART;VALUE=DATE-TIME:20220215T163000Z
DTEND;VALUE=DATE-TIME:20220215T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/55
DESCRIPTION:Title: Properly proximal von Neumann Algebras\nby Jesse Peterson
(Vanderbilt) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nPr
operly proximal groups were introduced recently by Boutonnet\, Ioana\, and
the speaker\, where they generalized several rigidity results to the sett
ing of higher-rank groups. In this talk\, I will describe how the notion o
f proper proximality fits naturally in the realm of von Neumann algebras.
I will also describe several applications\, including that the group von N
eumann algebra of a non-amenable inner-amenable group cannot embed into a
free group factor\, which solves a problem of Popa. This is joint work wit
h Changying Ding and Srivatsav Kunnawalkam Elayavalli.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandru Chirvasitu (Buffalo)
DTSTART;VALUE=DATE-TIME:20220222T163000Z
DTEND;VALUE=DATE-TIME:20220222T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/56
DESCRIPTION:Title: Flavors of rigidity\nby Alexandru Chirvasitu (Buffalo) as
part of Wales MPPM Mathematical Physics\n\n\nAbstract\nI will discuss a n
umber of results which\, though to my knowledge not mutually related in an
y direct manner\, nevertheless have a recognizably common flavor: "most" o
bjects of such-and-such a type have "few" symmetries. Examples abound\; th
e objects in question might be\n\n- finite graphs\, where "most" is interp
reted probabilistically and asymptotically as the graphs grow\;\n\n- quant
um graphs (i.e. appropriately well-behaved subspaces of matrix algebras)\,
where "most" means "along a Zariski-dense subset"\;\n\n- measured metric
spaces\, with "most" = "over a residual set in the measured Gromov-Hausdor
ff topology"\;\n\n- Riemannian manifolds\, "most" meaning "over an open de
nse set in the smooth topology".\n\n"Few symmetries" is also subject to ri
ch interpretation: it might mean a trivial automorphism group\, or a quant
um-group version thereof\, or that the automorphism group can be prescribe
d beforehand.\n\n(partly joint w/ Mateusz Wasilewski)\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amanda Young (TU Munich)
DTSTART;VALUE=DATE-TIME:20220301T163000Z
DTEND;VALUE=DATE-TIME:20220301T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/57
DESCRIPTION:Title: A bulk gap in the presence of edge states for a Haldane pseud
opotential\nby Amanda Young (TU Munich) as part of Wales MPPM Mathemat
ical Physics\n\n\nAbstract\nIn this talk\, we discuss a recent result on a
bulk gap for a truncated Haldane \npseudopotential with maximal half fill
ing\, which describes a strongly correlated system of spinless bosons in a
cylinder geometry. For this Hamiltonian with either open or periodic boun
dary conditions\, we prove a spectral gap above the highly degenerate grou
nd-state space which is uniform in the volume and particle number. Our pro
ofs rely on identifying invariant subspaces to which we apply gap-estimate
methods previously developed only for quantum spin Hamiltonians. In the c
ase of open boundary conditions\, the lower bound on the spectral gap accu
rately reflects the presence of edge states\, which do not persist into th
e bulk. Customizing the gap technique to the invariant subspace\, we avoid
the edge states and establish a more precise estimate on the bulk gap in
the case of periodic boundary conditions. The same approach can also be ap
plied to prove a bulk gap for the analogously truncated 1/3-filled Haldane
pseudopotential for the fractional quantum Hall effect. Based off joint w
ork with S. Warzel.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/57/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elizabeth Gillaspy (Montana)
DTSTART;VALUE=DATE-TIME:20220315T163000Z
DTEND;VALUE=DATE-TIME:20220315T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/58
DESCRIPTION:Title: K-theory for real k-graph C*-algebras\nby Elizabeth Gilla
spy (Montana) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nPu
rely infinite simple real C*-algebras\, like their complex counterparts\,
are classified by their K-theory. Indeed\, there are purely infinite simp
le real C*-algebras (e.g. the exotic Cuntz algebra E_n) whose existence is
only known thanks to K-theory computations. Our long-term goal\, in this
joint research project with Jeff Boersema\, is to construct more concrete
models for such C*-algebras. We begin by showing how k-graphs\, or highe
r-rank graphs (which are a higher-dimensional generalization of directed g
raphs)\, can give rise to purely infinite simple real C*-algebras. To eva
luate whether this class of real k-graph C*-algebras includes E_n\, we nee
d to compute the K-theory of real k-graph C*-algebras. To that end\, we a
dapt the spectral sequence studied by D.G. Evans\, which converges to the
K-theory of a complex k-graph C*-algebra\, to the setting of real C*-algeb
ras. Using this spectral sequence\, we compute K-theory for several exampl
es of real k-graph C*-algebras. \nThis is joint work with Jeff Boersema.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/58/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Reutter (Bonn)
DTSTART;VALUE=DATE-TIME:20220308T163000Z
DTEND;VALUE=DATE-TIME:20220308T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/59
DESCRIPTION:Title: Fusion 2-categories\, their Drinfeld centers\, and the minima
l modular extension conjecture\nby David Reutter (Bonn) as part of Wal
es MPPM Mathematical Physics\n\n\nAbstract\nA modular tensor category is a
ribbon category without any non-trivial transparent object\, while a supe
r-modular category is a ribbon category with a single transparent fermion.
In this talk\, I will sketch a proof of the "minimal modular extension co
njecture" stating that any super-modular category admits an index-2 extens
ion to a modular category. Along the way\, I will introduce various key p
layers of this proof\, such as fusion 2-categories and their Drinfeld cent
ers. This is based on arXiv:2105.15167 and is joint work with Theo Johnson
-Freyd.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/59/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexis Virelizier (Lille)
DTSTART;VALUE=DATE-TIME:20220322T163000Z
DTEND;VALUE=DATE-TIME:20220322T180000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/60
DESCRIPTION:Title: State sum invariants of homotopy classes of maps\nby Alex
is Virelizier (Lille) as part of Wales MPPM Mathematical Physics\n\n\nAbst
ract\nHomotopy quantum field theories (HQFTs) generalize topological quant
um field theories (TQFTs) by replacing manifolds by maps from manifolds to
a fixed target space X. In particular\, such an HQFT associates a scalar
invariant under homotopies to each map from a closed manifold to X. In thi
s talk\, I will explain how to generalize the state sum Turaev-Viro-Barett
-Westburry TQFT to an HQFT with target X in the following two cases. First
when X is a 1-type using fusion categories graded by a group (joint work
with Vladimir Turaev). Second when X is a 2-type using fusion categories g
raded by a crossed module (joint work with Kursat Sozer).\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/60/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bethany Marsh (Leeds)
DTSTART;VALUE=DATE-TIME:20220510T153000Z
DTEND;VALUE=DATE-TIME:20220510T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/61
DESCRIPTION:Title: An introduction to tau-exceptional sequences\nby Bethany
Marsh (Leeds) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nJo
int work with Aslak Bakke Buan (NTNU).\n \nWe introduce the notion of a ta
u-exceptional sequence for a finite dimensional algebra\, which can be reg
arded as the generalisation of a classical exceptional sequence considered
in the hereditary case. The new sequences behave well for both non-heredi
tary and hereditary algebras. The work is motivated by the signed exceptio
nal sequences introduced\, in the hereditary case\, by Igusa-Torodov\, and
by tau-tilting theory.\n \nWe also introduce a notion of a signed tau-exc
eptional sequence and show that there is a bijection between the set of co
mplete signed tau-exceptional sequences and ordered basic support tau-tilt
ing objects.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/61/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jamie Vicary (Cambridge)
DTSTART;VALUE=DATE-TIME:20220517T153000Z
DTEND;VALUE=DATE-TIME:20220517T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/62
DESCRIPTION:Title: HIGHER CATEGORIES AND QUANTUM COMPUTATION\nby Jamie Vicar
y (Cambridge) as part of Wales MPPM Mathematical Physics\n\n\nAbstract\nI
will show how some fundamental computational processes\, including\nencryp
ted communication and quantum teleportation\, can be defined in\nterms of
the higher representation theory of defects between 2d\ntopological cobord
isms\, giving insight into fundamental questions in\nclassical and quantum
computation. Everything will be explained from\nfirst principles\, with l
ots of pictures!\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/62/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hannes Thiel (Kiel)
DTSTART;VALUE=DATE-TIME:20220607T153000Z
DTEND;VALUE=DATE-TIME:20220607T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/63
DESCRIPTION:Title: Are C*-algebras determined by their linear and orthogonality
structure?\nby Hannes Thiel (Kiel) as part of Wales MPPM Mathematical
Physics\n\n\nAbstract\nIt is well-known that every C*-algebra is determine
d by its linear and\nmultiplicative structure: Two C*-algebras are *-isomo
rphic if and only\nif they admit a multiplicative\, linear bijection.\n\nW
e study if instead of the whole multiplicative structure it suffices to\nr
ecord when two elements have zero product. While it is not clear if\nevery
C*-algebra is determined this way\, we obtain many positive\nresults. In
particular\, two unital\, simple C*-algebras are *-isomorphic\nif and only
if they admit a linear bijection that preserves zero products.\n\nThis is
joint work with Eusebio Gardella.\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/63/
END:VEVENT
BEGIN:VEVENT
SUMMARY:George Elliott (Toronto)
DTSTART;VALUE=DATE-TIME:20220531T153000Z
DTEND;VALUE=DATE-TIME:20220531T170000Z
DTSTAMP;VALUE=DATE-TIME:20220528T193502Z
UID:MathematicalPhysics/64
DESCRIPTION:Title: Classification of C*-algebras - simple vs. non-simple\nby
George Elliott (Toronto) as part of Wales MPPM Mathematical Physics\n\n\n
Abstract\n\n Well-behaved simple C*-algebras (ver
y simple axioms)

\n\n\n\n
have now been classified. This now leaves the less well

\n\n\n\nbehaved simple case (some evidence!
)\, and the non-simple

\n\n\n\n\n\nalready a number of results in
the well-behaved non-simple

\n\n\n\ncase.

\n\n
LOCATION:https://researchseminars.org/talk/MathematicalPhysics/64/
END:VEVENT
END:VCALENDAR