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BEGIN:VEVENT
SUMMARY:Michele Del Zotto (Uppsala)
DTSTART;VALUE=DATE-TIME:20220308T150000Z
DTEND;VALUE=DATE-TIME:20220308T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/1
DESCRIPTION:Title: G
lobal structures from the infrared\nby Michele Del Zotto (Uppsala) as
part of Symmetry Seminar\n\n\nAbstract\nQuantum field theories with identi
cal local dynamics can admit different choices of global structure\, leadi
ng to different partition functions and spectra of extended operators. Rec
ent work has determined the structure of such choices via stringy geometri
c methods for various classes of Lagrangian and non-Lagrangian theories. I
n this talk I will discuss a purely field theoretical counterpart of this
analysis\, showing that global structures can be captured from a careful a
nalysis of the infrared Coulomb-like phases. Our results confirm and exten
d the many results obtained within geometric engineering about the global
structures of Argyres-Douglas theories\, 5d SCFTs and 6d SCFTs.\n
LOCATION:https://researchseminars.org/talk/SymSem/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Justin Kaidi (SCGP)
DTSTART;VALUE=DATE-TIME:20220315T140000Z
DTEND;VALUE=DATE-TIME:20220315T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/2
DESCRIPTION:Title: K
ramers-Wannier-like duality defects in (3+1)d gauge theories\nby Justi
n Kaidi (SCGP) as part of Symmetry Seminar\n\n\nAbstract\nI will introduce
a class of non-invertible topological defects in (3+1)d gauge theories wh
ose fusion rules are the higher-dimensional analogs of those of the Kramer
s-Wannier defect in the (1+1)d critical Ising model. As in the lower-dimen
sional case\, the presence of such non-invertible defects implies self-dua
lity under a particular gauging of the discrete (higher-form) symmetries.
I will illustrate this by means of the examples of SO(3) Yang-Mills at θ=
π\, as well as SU(2)N=4 SYM at τ=i.\n
LOCATION:https://researchseminars.org/talk/SymSem/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ho Tat Lam (MIT)
DTSTART;VALUE=DATE-TIME:20220412T150000Z
DTEND;VALUE=DATE-TIME:20220412T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/3
DESCRIPTION:Title: N
on-invertible Condensation\, Duality and Triality Defects in 3+1d\nby
Ho Tat Lam (MIT) as part of Symmetry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Du Pei (Harvard)
DTSTART;VALUE=DATE-TIME:20220419T150000Z
DTEND;VALUE=DATE-TIME:20220419T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/4
DESCRIPTION:Title: O
n Symmetries of 2d TQFTs and the Equivariant Verlinde Formula\nby Du P
ei (Harvard) as part of Symmetry Seminar\n\n\nAbstract\nIn this talk\, we
will discuss (generalized) symmetries of 2d semisimple TQFTs. We will show
that\, in a special basis\, the 0-form symmetries always act as permutati
ons while 1-form symmetries act by phases. This leads to an explicit descr
iption of the gauging of these symmetries. These results can be used to be
tter understand compactifications of 6d (2\,0) theories. In particular\, w
e will use it to generalize the equivariant Verlinde formula to the case o
f general Lie groups\, which leads to many predictions for the geometry of
Hitchin moduli spaces.\n
LOCATION:https://researchseminars.org/talk/SymSem/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibrahima Bah (JHU)
DTSTART;VALUE=DATE-TIME:20220322T150000Z
DTEND;VALUE=DATE-TIME:20220322T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/5
DESCRIPTION:by Ibrahima Bah (JHU) as part of Symmetry Seminar\n\nAbstract:
TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ibou Bah (JHU)
DTSTART;VALUE=DATE-TIME:20220405T150000Z
DTEND;VALUE=DATE-TIME:20220405T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/6
DESCRIPTION:Title: G
eometry of decoupled fields\nby Ibou Bah (JHU) as part of Symmetry Sem
inar\n\n\nAbstract\nAbstract: In this talk I will discuss aspects of flipp
ed fields that appear in the engineering of 4d SCFTs from compactification
s of 6d (1\,0) SCFTs of A_(N-1) type. By studying various ways of constru
cting the anomaly polynomial for the 4d theory\, it is possible to account
for flipped fields when the 6d SCFT is compactified on a Riemann surface.
I will also discuss their geometric origin and their role along the RG f
low.\n
LOCATION:https://researchseminars.org/talk/SymSem/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Apoorv Tiwari (KTH)
DTSTART;VALUE=DATE-TIME:20220426T150000Z
DTEND;VALUE=DATE-TIME:20220426T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/7
DESCRIPTION:Title: T
opological Holography: Unifying Conventional and Unconventional Quantum Ph
ase Transitions\nby Apoorv Tiwari (KTH) as part of Symmetry Seminar\n\
n\nAbstract\nIn this talk\, I will describe an approach that uses an auxil
iary D+1-dimensional topological order\, typically a topological gauge the
ory\, to extract non-perturbative statements about the quantum phases and
phase transitions realized in D-dimensional quantum systems with a fixed g
lobal symmetry structure. I will exemplify this approach for D=1 and for t
he case where the symmetry structure corresponds to a finite Abelian group
.\n
LOCATION:https://researchseminars.org/talk/SymSem/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenzo di Pietro (Trieste)
DTSTART;VALUE=DATE-TIME:20220503T150000Z
DTEND;VALUE=DATE-TIME:20220503T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/8
DESCRIPTION:Title: F
actorization and Global symmetry in holography\nby Lorenzo di Pietro (
Trieste) as part of Symmetry Seminar\n\n\nAbstract\nBased on 2203.09537. I
n the context of toy models of holography arising from 3d Chern-Simons the
ory\, I will describe an approach in which\, rather than summing over bulk
geometries\, one gauges a one-form global symmetry of the bulk theory. Th
is ensures that the bulk theory has no global symmetries\, and it makes th
e partition function on spacetimes with boundaries coincide with that of a
modular-invariant 2d CFT on the boundary. In particular\, on wormhole geo
metries one finds a factorized answer for the partition function\n
LOCATION:https://researchseminars.org/talk/SymSem/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dongmin Gang (Seoul)
DTSTART;VALUE=DATE-TIME:20220510T150000Z
DTEND;VALUE=DATE-TIME:20220510T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/9
DESCRIPTION:Title: I
nfrared phases of 3D class R theories\nby Dongmin Gang (Seoul) as part
of Symmetry Seminar\n\n\nAbstract\nWe study IR phases of 3D class R theor
y associated to closed non-hyperbolic 3-manifolds. Non-hyperbolic 3-manifo
lds can be obtained by performing Dehn fillings on 1-cusped hyperbolic 3-
manifolds along exceptional slopes. In 3D-3D correspondence\, the `excepti
onal' Dehn filling corresponds to the gauging of an SU(2) flavor symmetry
in a superconformal field theory associated to a 1-cusped 3-manifold with
`small' Chern-Simons levels. With several explicit examples\, we analyze
various interesting non-perturbative IR phenomena (such as spontaneous SU
SY breaking\, generation of mass gap and supersymmetry enhancement) from
the `exceptional' gaugings. Interestingly\, distinguished features of t
he IR phases can be captured by simple topological properties of non-hyper
bolic 3-manifolds. We also find that 3D class R theories associated to cer
tain classes of atoroidal non-hyperbolic manifolds always exhibit supersym
metry enhancement at low energy and actually flow to 3D rank 0 N=4 SCFTs
with trivial vacuum moduli space.\n
LOCATION:https://researchseminars.org/talk/SymSem/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ben Gripaios (Cambridge)
DTSTART;VALUE=DATE-TIME:20220726T150000Z
DTEND;VALUE=DATE-TIME:20220726T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/10
DESCRIPTION:Title:
Generalized symmetries of topological field theories\nby Ben Gripaios
(Cambridge) as part of Symmetry Seminar\n\n\nAbstract\nI describe joint wo
rk\, with Oscar Randal-Williams and Joseph Tooby-Smith\, studying generali
zed symmetries in a simplified arena in which the usual quantum field theo
ries of physics are replaced with topological field theories and the smoot
h structure with which the symmetry groups of physics are usually endowed
is forgotten. Doing so allows many questions of physical interest to be an
swered using the tools of homotopy theory. We study both global and gauge
symmetries\, as well as two types of `t Hooft anomaly. Our approach also a
llows some insight into earlier work on symmetries (generalized or not) of
topological field theories.\n
LOCATION:https://researchseminars.org/talk/SymSem/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yunqin Zheng (IPMU)
DTSTART;VALUE=DATE-TIME:20220621T150000Z
DTEND;VALUE=DATE-TIME:20220621T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/11
DESCRIPTION:by Yunqin Zheng (IPMU) as part of Symmetry Seminar\n\nAbstract
: TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Craig Lawrie (DESY)
DTSTART;VALUE=DATE-TIME:20220517T150000Z
DTEND;VALUE=DATE-TIME:20220517T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/12
DESCRIPTION:Title:
Global Structures in 6d (1\,0) SCFTs and Their Implications for 4d\nby
Craig Lawrie (DESY) as part of Symmetry Seminar\n\n\nAbstract\nWe explore
the global structure of the global symmetry group across the vast landsca
pe of 6d (1\,0) SCFTs. Many of the known 6d SCFTs fall into families relat
ed by Higgs branch deformations\, where the deformations are associated to
either a nilpotent orbit\, or a homomorphism from a finite group into E_8
\; we determine how the flavor group can be written simply in terms of thi
s data. A large class of novel 4d N=2 SCFTs can be obtained by compactifyi
ng these 6d (1\,0) SCFTs with non-simply-connected flavor group on a torus
in the presence of a topologically non-trivial flat flavor bundle charact
erized by a 't Hooft magnetic flux. We explore the properties of the resul
ting 4d theories and highlight where there is overlap with previously stud
ied constructions\, such as class S and the N=2 S-folds.\n
LOCATION:https://researchseminars.org/talk/SymSem/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yichul Choi (Stony Brook)
DTSTART;VALUE=DATE-TIME:20220531T150000Z
DTEND;VALUE=DATE-TIME:20220531T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/13
DESCRIPTION:Title:
Higher Berry Phase of Free Dirac Fermions\nby Yichul Choi (Stony Brook
) as part of Symmetry Seminar\n\n\nAbstract\nThe infrared fixed point of a
trivially gapped quantum field theory is described by an invertible field
theory\, which captures its response to various external background field
s. The set of background fields can include spacetime-dependent coupling c
onstants\, in which case we call the corresponding invertible theory a par
ameterized invertible field theory. The partition function of a parameteri
zed invertible field theory is called a higher Berry phase\, as it capture
s the response of the theory to the adiabatic variation of the coupling co
nstants across spacetime. I'll discuss a class of such parameterized inver
tible field theories arising from free Dirac fermions with spacetime-depen
dent mass parameters. The universal form of the higher Berry curvature wil
l be derived using the APS index theorem\, and an example of a nontrivial
parameterized invertible theory with a vanishing Berry curvature will be e
xplained.\n
LOCATION:https://researchseminars.org/talk/SymSem/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Irene Valenzuela (CERN)
DTSTART;VALUE=DATE-TIME:20220628T140000Z
DTEND;VALUE=DATE-TIME:20220628T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/14
DESCRIPTION:Title:
What can we learn from the absence of global symmetries?\nby Irene Val
enzuela (CERN) as part of Symmetry Seminar\n\n\nAbstract\nIn this talk I w
ill explain some of the implications that the absence of global symmetries
can have for the dynamics of the theory. I will review the reasoning behi
nd the absence of global symmetries in quantum gravity\, which is equivale
nt to requiring the absence of non-trivial topologocial operators. I will
then explain how many string theory features can be derived from this stat
ement\, including completeness of the charge spectra\, the existence of lo
calised worldvolume degrees of freedom on defects and the presence of axio
ns.\n
LOCATION:https://researchseminars.org/talk/SymSem/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theo Johnson-Freyd (Perimeter)
DTSTART;VALUE=DATE-TIME:20221004T140000Z
DTEND;VALUE=DATE-TIME:20221004T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/15
DESCRIPTION:Title:
A 4D TQFT which is not (quite) a gauge theory\nby Theo Johnson-Freyd (
Perimeter) as part of Symmetry Seminar\n\n\nAbstract\nSome people have acc
used me of proving that every (nice enough) 4D TQFT is equivalent to a gau
ge theory. A version of this statement is true\, but only if your notion o
f "gauge theory" allows dynamical spin structures among the "gauge fields"
\, and some rather complicated terms in the Lagrangian that couple the spi
n structures to the other gauge fields. That said\, many of these 4D TQFTs
also admit "dual" descriptions as true gauge theories for higher-form gro
ups. In this talk\, I will explain exactly which 4D TQFTs are equivalent t
o true (higher-group) gauge theories theories\, and present a minimal coun
terexample to the belief that all 4D TQFTs are true gauge theories.\n
LOCATION:https://researchseminars.org/talk/SymSem/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Maissam Barkeshli (Maryland)
DTSTART;VALUE=DATE-TIME:20221011T140000Z
DTEND;VALUE=DATE-TIME:20221011T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/16
DESCRIPTION:Title:
Defects and higher symmetries in (3+1)D topological phases of matter\n
by Maissam Barkeshli (Maryland) as part of Symmetry Seminar\n\n\nAbstract\
n(3+1)D topological phases of matter can host interesting classes of non-t
rivial topological defects of varying codimension\, of which the well-know
n point charges and flux loops are special cases. The complete algebraic s
tructure of these defects defines a higher category\, and can be viewed as
an emergent higher symmetry. This plays an important role both in the cla
ssification of phases of matter and the possible fault-tolerant logical op
erations in quantum error correcting codes. In this talk I will discuss so
me recent progress in our understanding of the properties of invertible de
fects and higher group symmetries in (3+1)D topological phases of matter.
Along the way I will review some progress over the past few years in chara
cterizing topological phases of matter and their defects in low dimensions
.\n
LOCATION:https://researchseminars.org/talk/SymSem/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Ferrari (Durham)
DTSTART;VALUE=DATE-TIME:20221018T140000Z
DTEND;VALUE=DATE-TIME:20221018T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/17
DESCRIPTION:Title:
Non-invertible Symmetries and Higher Representation Theory\nby Andrea
Ferrari (Durham) as part of Symmetry Seminar\n\n\nAbstract\nThere has rece
ntly been a lot of excitement surrounding non-invertible global symmetries
and their potential applications. An important question is how to systema
tically construct theories whose non-invertible symmetry categories we can
control well. In this talk I will suggest that higher representation theo
ry can help us to answer this question when the symmetries are non-intrins
ically non-invertible. In particular\, I will explain how the topological
defects obtained after gauging finite groups and 2-groups in 3 dimensions
form the category of 2-representations of the original 2-group\, and how t
his fact can be applied to some gauge theories with disconnected gauge gro
ups. The same techniques can be extended to more general higher groups and
subgroups in higher dimensions.\n
LOCATION:https://researchseminars.org/talk/SymSem/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Reutter (Hamburg)
DTSTART;VALUE=DATE-TIME:20221101T150000Z
DTEND;VALUE=DATE-TIME:20221101T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/18
DESCRIPTION:Title:
Higher fusion categories and their fusion rings\nby David Reutter (Ham
burg) as part of Symmetry Seminar\n\n\nAbstract\nHigher fusion categories
are certain algebraic gadgets which capture some of the behavior of topolo
gical operators/defects in higher-dimensional quantum field theories. \n\n
In the first part of this talk\, I will give an introduction to the basic
concepts of higher fusion category theory and overview some key examples.
If time permits\, I will then explain how every fusion n-category C has as
sociated `homotopy sets' pi_k C\, defined as a certain quotient of the set
of (k+1)-codimensional operators. I will sketch how these sets pi_k C car
ry a kind of fusion ring structure and how in the modular case this fusion
ring structure can be recovered from a higher-dimensional Verlinde formul
a.\n\n \n\nThe first part of this talk is based on arXiv:1812.11933 (joint
with Christopher Douglas)\, the second part is based on ongoing joint wor
k with Theo Johnson-Freyd.\n
LOCATION:https://researchseminars.org/talk/SymSem/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xiao-Gang Wen (MIT)
DTSTART;VALUE=DATE-TIME:20221108T150000Z
DTEND;VALUE=DATE-TIME:20221108T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/19
DESCRIPTION:Title:
A classification of 3+1D topological orders and non-degenerate unitary bra
ided fusion 2-category\nby Xiao-Gang Wen (MIT) as part of Symmetry Sem
inar\n\n\nAbstract\nI will discuss the microscopic definition of topologic
al orders in 3d space and its connection with non-degenerate unitary braid
ed fusion 2-categories (or unitary fusion 3-categories with trivial center
). Then I will discuss a "physical" classification of 3+1D topological or
ders (and non-degenerate unitary braided fusion 2-categories or unitary fu
sion 3-categories with trivial center).\n
LOCATION:https://researchseminars.org/talk/SymSem/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fiona Burnell (Minnesota)
DTSTART;VALUE=DATE-TIME:20221025T140000Z
DTEND;VALUE=DATE-TIME:20221025T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/20
DESCRIPTION:Title:
Subsystem symmetry protected phases and anomalies in higher-form gauge the
ories\nby Fiona Burnell (Minnesota) as part of Symmetry Seminar\n\n\nA
bstract\nRecent interest in systems with excitations that have sub-dimensi
onal mobility and conserved higher-multipole moments has motivated an inve
stigation of models with so-called subsystem symmetry\, in which conservat
ion laws apply not to the system as a whole\, but rather to sub manifolds
within the system\, such as families of lattice planes. I will discuss ana
logs of symmetry protection in these phases\, and its relation to anomalie
s in the corresponding field theoretical description\, which involves tens
or gauge fields.\n
LOCATION:https://researchseminars.org/talk/SymSem/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Javier Mangan (UPenn)
DTSTART;VALUE=DATE-TIME:20221115T150000Z
DTEND;VALUE=DATE-TIME:20221115T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/21
DESCRIPTION:Title:
Generalized symmetries\, Noether and Weinberg-Witten\nby Javier Mangan
(UPenn) as part of Symmetry Seminar\n\n\nAbstract\nIn this talk we descri
be new theorems concerning the mixing of symmetries in QFT. In particular\
,\nwe show that generalized symmetries cannot be charged under a continuou
s global symmetry having a Noether\ncurrent. The results follow from a fin
er classification of twist operators\, which naturally extends to\nfinite
group global symmetries. They unravel topological obstructions to the stro
ng version of Noether’s\ntheorem in QFT\, even if under general conditio
ns a global symmetry can be implemented locally by twist\noperators (weak
version). We use these results to rederive Weinberg-Witten’s theorem wit
hin local QFT\,\ngeneralizing it in several directions. We end up discussi
ng the conditions for the strong version to hold\,\ndynamical aspects of Q
FT’s with non-compact generalized symmetries\, scale vs conformal invari
ance in QFT\nand connections with the Coleman-Mandula theorem.\n
LOCATION:https://researchseminars.org/talk/SymSem/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christian Copetti (SISSA)
DTSTART;VALUE=DATE-TIME:20221122T150000Z
DTEND;VALUE=DATE-TIME:20221122T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/22
DESCRIPTION:Title:
Zoology of duality defects: the view from class S\nby Christian Copett
i (SISSA) as part of Symmetry Seminar\n\n\nAbstract\nWe review known const
ructions of non-invertible duality defects for general QFTs and explain th
eir emergence in the context of theories of class S. This leads us to defi
ning the of "rank" of a non-invertible symmetry. We explain to compute it
and its impact the fusion algebra.\n\nBased on upcoming work with A. Antin
ucci\, G. Galati and G. Rizi.\n
LOCATION:https://researchseminars.org/talk/SymSem/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Yu (Perimeter)
DTSTART;VALUE=DATE-TIME:20221206T150000Z
DTEND;VALUE=DATE-TIME:20221206T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/23
DESCRIPTION:Title:
Gauging noninvertible surface operators\, and the 2-Deligne theorem.\n
by Matthew Yu (Perimeter) as part of Symmetry Seminar\n\n\nAbstract\nI wil
l explain a generalization of the notion of an anomaly for a symmetry to a
noninvertible symmetry enacted by surface operators using the framework o
f condensation in 2-categories. I will give examples of when we have reaso
nable control over these anomalies\, and prove theorems about the structur
e of the 2-category obtained by condensing a suitable algebra object. I w
ill provide examples where the resulting category displays grouplike fusio
n rules and through a cohomology computation\, find the obstruction to con
densing further to the vacuum theory. I will then present the main result
of this work\, which categorifies a theorem of Deligne about the existence
of fibre functors for 1-categories. This work was done in collaboration
with Thibault Decoppet.\n
LOCATION:https://researchseminars.org/talk/SymSem/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fabio Apruzzi (Bern)
DTSTART;VALUE=DATE-TIME:20221129T150000Z
DTEND;VALUE=DATE-TIME:20221129T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/24
DESCRIPTION:Title:
Non-invertible symmetries from holography and branes\nby Fabio Apruzzi
(Bern) as part of Symmetry Seminar\n\n\nAbstract\nGeneralised non-inverti
ble symmetries have emerged in past year as a new type of symmetry in d≥
4 QFTs. This has lead to a new understanding of certain constraints on th
e low-energy dynamics of QFTs\, such as QED\, or the standard model. In th
is talk\, I will describe a systematic approach to deriving symmetry gener
ators of Quantum Field Theories in holography. Central to this are the Gau
ss law constraints in the Hamiltonian quantization of Symmetry Topological
Field Theories (SymTFTs)\, which are obtained from supergravity. Cruciall
y\, we realize the symmetry generators from world-volume theories of D-bra
nes in holography. I will particularly focus on non-invertible symmetries\
, by presenting the application of our proposal in the holographic setup\,
dual to 4d N=1 SU(M) or PSU(M) Super-Yang Mills (SYM). In the brane-pictu
re\, the fusion of non-invertible symmetries naturally arises from the Mye
rs effect on D-branes. In addition\, the action of the topological non-inv
ertible defects t’Hooft on line is modelled by the Hanany-Witten effect.
For SU and PSU SYM\, we also identify the infra-red (IR) 4d field theory
from the dual gravity description\, which describes the domain-walls and c
onfining/deconfining behaviour in the IR.\n
LOCATION:https://researchseminars.org/talk/SymSem/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lian Kong (SIQSE\, Southern University of Science and Technology)
DTSTART;VALUE=DATE-TIME:20230117T140000Z
DTEND;VALUE=DATE-TIME:20230117T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/25
DESCRIPTION:Title:
Global Quantum Many-body Theory\nby Lian Kong (SIQSE\, Southern Univer
sity of Science and Technology) as part of Symmetry Seminar\n\n\nAbstract\
nThe program of studying the categories of topological orders or quantum l
iquids\, was initiated in 1502.01690 and 1702.00673\, where the notion of
a morphism between two topological orders (or quantum liquids) was introdu
ced. This notion is different from the usual definition by a domain wall b
ut contains the recent idea of Symmetry TFT as special cases. In this talk
\, I will review this notion and show how it led us immediately to the so-
called boundary-bulk relation\, then to a unified theory of both gapped an
d gapless boundaries of 2+1D topological orders and topological Wick rotat
ion 1705.01087\,1905.04924\,1912.01760\, and eventually to a mathematical
theory of gapped/gapless quantum liquids 2011.02859\, 2107.03858\, 2201.05
726\n
LOCATION:https://researchseminars.org/talk/SymSem/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nathan Seiberg (IAS)
DTSTART;VALUE=DATE-TIME:20230124T150000Z
DTEND;VALUE=DATE-TIME:20230124T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/26
DESCRIPTION:Title:
Symmetries and Anomalies in the Continuum and on the Lattice\nby Natha
n Seiberg (IAS) as part of Symmetry Seminar\n\n\nAbstract\nBased on joint
work with Meng Cheng (arXiv:2211.12543)\, we will discuss some aspects of
global symmetries and their ‘t Hooft anomalies.\nWe will define a notion
of an emanant global symmetry. It is not a symmetry of the UV theory\, b
ut unlike emergent (accidental) symmetries\, it is not violated by any rel
evant or irrelevant operators in the IR theory. \nWe will present lattice
models with anomalous internal symmetries and see how the anomalies are di
agnosed on the lattice using topological defects.\nWe will also discuss la
ttice models with anomalous lattice translation and relate them to an anom
alous emanant symmetry in the IR theory. This will connect our discussion
to the well-known Lieb-Schultz-Mattis theorem and to filling constraints
like Luttinger theorem.\n
LOCATION:https://researchseminars.org/talk/SymSem/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clay Cordova (Chicago)
DTSTART;VALUE=DATE-TIME:20230214T150000Z
DTEND;VALUE=DATE-TIME:20230214T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/27
DESCRIPTION:Title:
Neutrino Masses from Generalized Symmetry Breaking\nby Clay Cordova (C
hicago) as part of Symmetry Seminar\n\n\nAbstract\nWe explore generalized
global symmetries in theories of physics Beyond the Standard Model. Models
with Z' bosons generically contain `non-invertible' chiral symmetries\, w
hose presence indicates a natural paradigm to break this symmetry by an ex
ponentially small amount in an ultraviolet completion. For example\, in mo
dels of gauged lepton family difference\, there is a non-invertible lepton
number symmetry which protects neutrinomasses. We embed these theories in
gauged non-Abelian horizontal lepton symmetries\, e.g SU(3)_H\, where th
e generalized symmetries are broken non-perturbatively by the existence of
lepton family magnetic monopoles. In such theories\, either Majorana or D
irac neutrino masses may be generated through quantum gauge theory effects
from the charged lepton Yukawas. These theories require no bevy of new fi
elds nor ad hoc additional global symmetries\, but are instead simple\, na
tural\, and predictive: the discovery of a lepton family Z' at low energie
s will reveal the scale at which it emerges from a larger gauge symmetry.\
n
LOCATION:https://researchseminars.org/talk/SymSem/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lakshya Bhardwaj (Oxford)
DTSTART;VALUE=DATE-TIME:20230131T150000Z
DTEND;VALUE=DATE-TIME:20230131T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/28
DESCRIPTION:Title:
Non-Invertible Theta Symmetries\nby Lakshya Bhardwaj (Oxford) as part
of Symmetry Seminar\n\n\nAbstract\nIt is by now well-known that the symmet
ries of a d-dimensional quantum field theory form a fusion (d-1)-category.
This contains a fusion 1-category piece formed by genuine topological lin
e operators and non-genuine topological local operators which is extremely
well understood both physically and mathematically. This talk will discus
s recent physical and mathematical understandings of a fusion 2-category p
iece formed by genuine topological surface operators and non-genuine topol
ogical line & local operators\, which contains within it the above fusion
1-category piece. For simplest physical constructions\, the fusion 2-categ
ory can be identified with the 2-category formed by 2-representations of a
finite group G. We will discuss the mathematical definition of 2-represen
tations and provide a simple universal physical reasoning for their appear
ance: namely that any QFT that can be obtained by gauging a 0-form symmetr
y group G contains dual non-invertible symmetries described by surface ope
rators labeled by 2-representations of G. We refer to such universal symme
tries as theta symmetries because they generalize the notion of theta angl
e. We will then proceed to discuss the inclusion of non-universal symmetri
es that depend on the specifics of the QFT under consideration. We will se
e that the physical reasoning involved in the discussion of universal thet
a symmetries will continue to play a major role also for non-universal sym
metries\, leading to the notion of "twisted theta symmetries". Many intere
sting physical phenomena like symmetry fractionalization on condensation d
efects will be encountered. Towards the end of the talk\, we will briefly
discuss the generalization of these studies to fusion 3-categories and hig
her. This involves various physical and mathematical subtleties having to
do with the fact that TQFTs in spacetime dimension bigger than two form an
extremely rich mathematical structure.\n
LOCATION:https://researchseminars.org/talk/SymSem/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emily Nardoni (Kavli IPMU)
DTSTART;VALUE=DATE-TIME:20230221T140000Z
DTEND;VALUE=DATE-TIME:20230221T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/29
DESCRIPTION:Title:
Probing Anomalies of Non-Invertible Symmetries with Symmetry TFTs\nby
Emily Nardoni (Kavli IPMU) as part of Symmetry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miguel Montero (Madrid)
DTSTART;VALUE=DATE-TIME:20230228T150000Z
DTEND;VALUE=DATE-TIME:20230228T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/30
DESCRIPTION:Title:
The Chronicles of IIBordia\nby Miguel Montero (Madrid) as part of Symm
etry Seminar\n\n\nAbstract\nWe will embark on a journey through the realms
of cobordism groups in IIB string theory\, taking into account the dualit
y symmetry of the theory. These cobordism groups are interesting because t
hey can be used systematically to predict new generalized symmetries of II
B supergravity and the corresponding objects that break them in IIB string
theory. In this way we are able to recover many known branes and a few un
known ones. We will describe some particularly interesting examples\, disc
uss the connection to topological couplings and anomalies in IIB string th
eory\, and time permitting\, I will comment on the likely fate of non-inve
rtible symmetries in quantum gravity.\n
LOCATION:https://researchseminars.org/talk/SymSem/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zohar Komargodski (SCGP)
DTSTART;VALUE=DATE-TIME:20230321T150000Z
DTEND;VALUE=DATE-TIME:20230321T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/31
DESCRIPTION:Title:
Line Operators\, RG Flows\, and One-Form Symmetry\nby Zohar Komargodsk
i (SCGP) as part of Symmetry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wenjie Ji (UCSB)
DTSTART;VALUE=DATE-TIME:20230328T140000Z
DTEND;VALUE=DATE-TIME:20230328T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/32
DESCRIPTION:Title:
Recent progress in the symmetry/topological order correspondence\nby W
enjie Ji (UCSB) as part of Symmetry Seminar\n\n\nAbstract\nIn this talk\,
we discuss some recent progress in the symmetry/topological order correspo
ndence. The correspondence basically says that topological aspects of a di
screte symmetry in d dimensions are captured by topological data in a topo
logical order in d+1 dimensions. The topological aspects of symmetry inclu
de but are not limited to symmetry charges\, defects\, their fusion rules
as well as commutation relations. We will discuss (1) how a beyond-Landau
transition is solved using the correspondence (arXiv: 2205.06244) and (2)
in practice how we derive a topological order for a given symmetry in a 1+
1d conformal field theory (arXiv:2106.02069). For the latter\, two cases a
re particularly interesting: (i) when the symmetry is anomalous\, (ii) aft
er the CFT is matched with a topological order\, there is a further symmet
ry that enriches the topological order. If time allowed\, we discuss the s
imilarities and relations of our setting with that proposed by Freed\, Moo
re\, and Teleman.\n
LOCATION:https://researchseminars.org/talk/SymSem/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Brennan (UCSD)
DTSTART;VALUE=DATE-TIME:20230404T140000Z
DTEND;VALUE=DATE-TIME:20230404T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/33
DESCRIPTION:Title:
Coupling a Cosmic String to a TQFT\nby Daniel Brennan (UCSD) as part o
f Symmetry Seminar\n\n\nAbstract\nIn this talk we will study a model that
couples axion-Maxwell theory to a TQFT. Here\, we will show that there are
phenomenological consequences of this coupling and leave potentially meas
urable effects from the cosmological evolution of our universe.\n
LOCATION:https://researchseminars.org/talk/SymSem/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pavel Putrov (ICTP)
DTSTART;VALUE=DATE-TIME:20230411T140000Z
DTEND;VALUE=DATE-TIME:20230411T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/34
DESCRIPTION:Title:
Non-invertible symmetries and mixed gravitational anomalies\nby Pavel
Putrov (ICTP) as part of Symmetry Seminar\n\n\nAbstract\nIn my talk I will
describe how a presence of a mixed anomaly between a global symmetry and
gravity can be traded off for non-invertibility of the charge operators. S
pecifically\, I will consider the cases of U(1) and Z4 symmetries (which i
nclude fermion parity) in 4d. I will also comment on the relevance for the
Standard Model. The talk is based on a joint work with Juven Wang.\n
LOCATION:https://researchseminars.org/talk/SymSem/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ruben Verresen (Harvard)
DTSTART;VALUE=DATE-TIME:20230509T140000Z
DTEND;VALUE=DATE-TIME:20230509T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/35
DESCRIPTION:Title:
Higgs condensates are symmetry-protected topological phases: from cluster
states to superconductors\nby Ruben Verresen (Harvard) as part of Symm
etry Seminar\n\n\nAbstract\nDeconfined phases of gauge theories are now we
ll-understood as spontaneously breaking higher-form symmetries. How does t
he Higgs phase fit in this way of thinking? In this talk\, we will explore
how the Higgs phase does not just preserve such a higher-form symmetry\,
but is in a non-trivial symmetry-protected topological (SPT) phase. This s
heds new light on the distinction between confined and Higgs phases. In fa
ct\, the remarkable properties of superconductors---which are Higgs phases
for U(1) gauge theory---can be derived as SPT properties! This is based o
n the works arxiv:2010.00607\, arxiv:2211.01376 and arxiv:2303.08136.\n
LOCATION:https://researchseminars.org/talk/SymSem/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Clement Delcamp (Ghent)
DTSTART;VALUE=DATE-TIME:20230516T140000Z
DTEND;VALUE=DATE-TIME:20230516T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/36
DESCRIPTION:Title:
Higher categorical symmetries and gauging on the lattice\nby Clement D
elcamp (Ghent) as part of Symmetry Seminar\n\n\nAbstract\nHigher categoric
al symmetries have received widespread attention in recent years. Though e
xotic\, such generalised symmetries have been shown to naturally arise as
dual symmetries upon gauging invertible symmetries. Given an arbitrary two
-dimensional lattice model with an ordinary symmetry\, I will present an a
pproach to perform the (twisted) gauging of any of its sub-symmetries and
study the resulting symmetry structure. Specialising to certain finite gro
up generalisations of the (2+1)d transverse-field Ising model\, I will exp
licitly construct lattice symmetry operators organised into fusion 2-categ
ories of higher representations of higher groups.\n
LOCATION:https://researchseminars.org/talk/SymSem/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gregory Moore (Rutgers)
DTSTART;VALUE=DATE-TIME:20230523T140000Z
DTEND;VALUE=DATE-TIME:20230523T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/37
DESCRIPTION:Title:
Finite Symmetries Of Field Theories From TQFT\nby Gregory Moore (Rutge
rs) as part of Symmetry Seminar\n\n\nAbstract\nI will review some aspects
of the paper ``Topological Field Theory In Quantum Field Theory\,'' writte
n with Dan Freed and Constantin Teleman. I will review some aspects of fin
ite homotopy theories\, which form the main source of examples in the pape
r\, and attempt to give a talk complementary to the several excellent talk
s by Freed and Teleman already available online.\n
LOCATION:https://researchseminars.org/talk/SymSem/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simone Giacomelli (Milano)
DTSTART;VALUE=DATE-TIME:20230502T140000Z
DTEND;VALUE=DATE-TIME:20230502T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/38
DESCRIPTION:Title:
Comments on Non-invertible Symmetries in Argyres-Douglas Theories\nby
Simone Giacomelli (Milano) as part of Symmetry Seminar\n\n\nAbstract\nIn t
his seminar I discuss the presence of non-invertible symmetries in an infi
nite family of superconformal Argyres-Douglas theories. This class of theo
ries arises from diagonal gauging of the flavor symmetry of a collection o
f multiple copies of D_p(SU(N)) theories. The same set of theories that we
study can also be realized from 6d N=(1\,0) compactification on a torus.
The main example in this class is the (A_2\, D_4) theory\, which bears the
same structures of non-invertible duality and triality defects as those o
f N=4 super Yang-Mills with gauge algebra su(2). This result extends to in
finitely many other Argyres-Douglas theories in the same family\, includin
g those with central charges a=c whose conformal manifold is one dimension
al\, and those with a\\neq c whose conformal manifold has dimension larger
than one. This conclusion is supported by examining certain special cases
that can be realized in terms of theories of class S.\n
LOCATION:https://researchseminars.org/talk/SymSem/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Antinucci (Sissa)
DTSTART;VALUE=DATE-TIME:20230919T140000Z
DTEND;VALUE=DATE-TIME:20230919T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/39
DESCRIPTION:Title:
Anomalies of non-invertible self-duality symmetries: fractionalization and
gauging"\nby Andrea Antinucci (Sissa) as part of Symmetry Seminar\n\n
\nAbstract\nAnomalies of global symmetries are important tools for constra
ining the dynamics of QFTs\, hence their generalization to non-invertible
symmetries is clearly important. Their definition and classification\, how
ever\, are still puzzling. In this talk\, I will argue that defining anoma
lies as obstructions to gauging makes them computable using symmetry topol
ogical field theory (SymmTFT). I will focus on duality defects\, arising i
n d=2n dimensional theories self-dual under gauging a finite abelian n-1 f
orm symmetry. For d=2\, the classification of anomalies was already known
in the mathematical literature\, and I will demonstrate how to reproduce t
hese results with techniques easily generalizable to higher dimensions. In
any dimension\, we find two obstructions to gauging. The first indicates
that intrinsically non-invertible symmetries are always anomalous. When th
is obstruction vanishes\, a second one can emerge\, linked to a pure anoma
ly in the global variant where the duality defect is invertible. Calculati
ng this requires extra data\, which I will argue corresponds to a choice o
f symmetry fractionalization. Based on joint work (2308.11707) with F. Ben
ini\, C. Copetti\, G. Galati\, G. Rizi.\n
LOCATION:https://researchseminars.org/talk/SymSem/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sal Pace (MIT)
DTSTART;VALUE=DATE-TIME:20230926T140000Z
DTEND;VALUE=DATE-TIME:20230926T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/40
DESCRIPTION:Title:
Emergent generalized symmetries in ordered phases and their spontaneous br
eaking.\nby Sal Pace (MIT) as part of Symmetry Seminar\n\n\nAbstract\n
Based on recent work (arXiv:2308.05730) and upcoming work with Chenchang Z
hu\, Agnès Beaudry\, and Xiao-Gang Wen\, we will discuss (non-)invertible
higher-form symmetries that emerge in generic ordered phases and their ph
ysical consequences. Such phases arise from spontaneously breaking an ordi
nary symmetry G down to a subgroup H\, are described in the deep IR by a n
onlinear sigma model with target space G/H\, and are ubiquitous to condens
ed matter and high energy physics. We will focus on two aspects of this st
ory: (1) when the generalized symmetry is finite\, the fusion higher categ
ory describing its symmetry defects\, and (2) its spontaneous breaking\, w
hich drives a phase transition to a nontrivial disordered phase with (non-
)abelian topological orders and emergent photons. We will present examples
for different groups G and H and construct lattice and continuum models t
hat realize the generalized symmetry's spontaneous symmetry-breaking phase
s.\n
LOCATION:https://researchseminars.org/talk/SymSem/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kantaro Ohmori (Tokyo)
DTSTART;VALUE=DATE-TIME:20231024T130000Z
DTEND;VALUE=DATE-TIME:20231024T140000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/41
DESCRIPTION:by Kantaro Ohmori (Tokyo) as part of Symmetry Seminar\n\nAbstr
act: TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Meng Cheng (Yale)
DTSTART;VALUE=DATE-TIME:20231031T150000Z
DTEND;VALUE=DATE-TIME:20231031T160000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/42
DESCRIPTION:by Meng Cheng (Yale) as part of Symmetry Seminar\n\nAbstract:
TBA\n
LOCATION:https://researchseminars.org/talk/SymSem/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marieke van Beest (SCGP)
DTSTART;VALUE=DATE-TIME:20231003T140000Z
DTEND;VALUE=DATE-TIME:20231003T150000Z
DTSTAMP;VALUE=DATE-TIME:20230925T230835Z
UID:SymSem/43
DESCRIPTION:Title:
Monopoles\, Scattering\, and Generalized Symmetries\nby Marieke van Be
est (SCGP) as part of Symmetry Seminar\n\n\nAbstract\nI will discuss the p
roblem of electrically charged\, massless fermions scattering off magnetic
monopoles. The interpretation of the outgoing states has long been a puzz
le\, as they can carry fractional quantum numbers. We argue that such outg
oing particles live in the twisted sector of a topological co-dimension 1
surface\, which ends topologically on the monopole. This surface is in gen
eral noninvertible\, and as such the outgoing radiation not only carries u
nconventional flavor quantum numbers\, but is trailed by a topological fie
ld theory\, which is a new prediction.\n
LOCATION:https://researchseminars.org/talk/SymSem/43/
END:VEVENT
END:VCALENDAR