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SUMMARY:Christopher Herzog (King's College London)
DTSTART;VALUE=DATE-TIME:20200520T130000Z
DTEND;VALUE=DATE-TIME:20200520T140000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/1
DESCRIPTION:Title: Graphene and boundary conformal field theory\nby Christopher Herzog (
King's College London) as part of SISSA HEP seminars\n\n\nAbstract\nThe in
frared fixed point of graphene under the renormalization group flow is a r
elatively under studied yet important example of a boundary conformal fiel
d theory with a number of remarkable properties. It has a close relationsh
ip with three dimensional QED. It maps to itself\nunder electric-magnetic
duality. Moreover\, it along with its supersymmetric cousins all possess a
n exactly marginal coupling -- the charge of the electron. I will review p
ast work on this model and also discuss my own contributions which have fo
cused on understanding the boundary contributions to the anomalous trace o
f the stress tensor and their role in helping to understand the structure
of boundary conformal field theory. I will also present some results on th
e hemisphere partition function for supergraphene\, its duality properties
\, and an exact computation of the conductivity at arbitrary values of the
interaction strength.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petr Kravchuk (IAS)
DTSTART;VALUE=DATE-TIME:20210113T140000Z
DTEND;VALUE=DATE-TIME:20210113T150000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/2
DESCRIPTION:Title: Light-ray operators\, detectors\, and OPEs\nby Petr Kravchuk (IAS) as
part of SISSA HEP seminars\n\n\nAbstract\nIn this talk I will review the
recent developments connected to light-ray operators in conformal field th
eories. Light-ray operators are non-local operators which perform an analy
tic continuation of the usual local operators in spin. In CFTs they are co
nnected to the recently discovered Lorentzian inversion formula and to som
e interesting representation theory. Furthermore\, they can be interpreted
as asymptotic observables\, generalizing event shapes such as energy-ener
gy correlators. Finally\, I will discuss how they control the small-angle
limit of energy-energy correlators.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sahand Seifnashri (Stony Brook U. SCGP)
DTSTART;VALUE=DATE-TIME:20210210T150000Z
DTEND;VALUE=DATE-TIME:20210210T160000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/3
DESCRIPTION:Title: Non-invertible Symmetries and Confinement in 2d Adjoint QCD\nby Sahan
d Seifnashri (Stony Brook U. SCGP) as part of SISSA HEP seminars\n\n\nAbst
ract\nAbstract: We will discuss the notion of "non-invertible symmetries"
that generalize group-like symmetries in QFTs. Using these generalized sym
metries we prove the deconfinement of the fundamental quark in 2d massless
adjoint QCD. When the adjoint quark has a small mass the theory confines
and the non-invertible symmetries are softly broken. We use them to analyt
ically compute the tension of the confining strings. We will also consider
the symmetric quartic fermion deformations that are protected by the non-
invertible symmetries\, thus violating the ordinary notion of naturalness.
\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/3/
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SUMMARY:Zoltan Bajnok (Wigner Research Centre for Physics)
DTSTART;VALUE=DATE-TIME:20210224T133000Z
DTEND;VALUE=DATE-TIME:20210224T143000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/4
DESCRIPTION:Title: From perturbative to non-perturbative in the O(4) sigma model\nby Zol
tan Bajnok (Wigner Research Centre for Physics) as part of SISSA HEP semin
ars\n\n\nAbstract\nIs it possible to derive non-perturbative contributions
in a quantum field theory\nknowing only the perturbative coefficients? We
answer this question affirmatively\nbased on the careful analysis of the
integrable two dimensional O(4) sigma model.\nWe investigate its ground st
ate energy in a magnetic field\, for which integrability\nprovides an exac
t linear integral equation. By cleverly expanding this equation\nwe could
calculate a large number of very percise\, factorially growing perturbativ
e\ncoefficients. By investigating their asymptotical behaviour on the Bore
l plane we\nmanaged to reveal a nice resurgence structure leading to the f
irst few exponentially\nsupressed non-perturbative terms of the ambiguity
free trans-series. We checked\nour results against the direct numerical s
olution of the exact integral equation\nand find complete agreement.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/4/
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SUMMARY:Guido Festuccia (Uppsala)
DTSTART;VALUE=DATE-TIME:20210310T133000Z
DTEND;VALUE=DATE-TIME:20210310T143000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/5
DESCRIPTION:Title: Consistency of supersymmetric 't Hooft anomalies\nby Guido Festuccia
(Uppsala) as part of SISSA HEP seminars\n\n\nAbstract\nI will consider rec
ent claims that supersymmetry is anomalous in the presence of a R-symmetry
anomaly\, revisit arguments that such an anomaly in supersymmetry can be
removed and write down an explicit counterterm that accomplishes it. Remov
al of the supersymmetry anomaly requires enlarging the corresponding curre
nt multiplet. As a consequence the Ward identities for other symmetries th
at are already anomalous acquire extra terms. This procedure is impeded on
ly when the choice of current multiplet is forced. We show how Wess-Zumino
consistency conditions are modified when the anomaly is removed. A check
that the modified Wess-Zumino consistency conditions are satisfied\, and s
upersymmetry is unbroken\, is possible via an explicit one loop computatio
n using Pauli-Villars regulators.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/5/
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SUMMARY:Monica Pate (Harvard)
DTSTART;VALUE=DATE-TIME:20210324T150000Z
DTEND;VALUE=DATE-TIME:20210324T160000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/6
DESCRIPTION:Title: Scattering Amplitudes on the Celestial sphere\nby Monica Pate (Harvar
d) as part of SISSA HEP seminars\n\n\nAbstract\nThe identification of quan
tum field theoretic soft theorems with constraints from infinite-dimension
al asymptotic symmetries offers exciting prospects for solving the scatter
ing problem in quantum gravity. In four spacetime dimensions\, the asymp
totic symmetry group includes the local conformal (Virasoro) symmetry of t
wo dimensions\, motivating the proposal that 4D scattering is holographi
cally dual to a 2D conformal theory. Lorentz symmetry in four dimensions
comprises the global part of the 2D conformal group of the dual. Asympto
tic particles in boost as opposed to standard momentum eigenstates transf
orm like primary operators\, and thereby manifestly exhibit the underlying
conformal symmetry. Scattering amplitudes for such states -- known as c
elestial amplitudes -- involve contributions from asymptotic particles of
arbitrarily high energy and accordingly do not respect the familiar paradi
gm of Wilsonian IR/UV decoupling. Nevertheless\, I will describe how vario
us observable IR and UV phenomena can be canonically extracted directly fr
om celestial amplitudes. Moreover\, a manifestly Lorentz covariant formul
ation of scattering constraints is necessary for their direct application
to celestial amplitudes. I will explain how constraints from Poincare sym
metry\, soft UV behavior of quantum gravity\, and asymptotic symmetries ar
e covariantly implemented in celestial amplitudes.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kristan Jensen (University of Victoria)
DTSTART;VALUE=DATE-TIME:20210407T123000Z
DTEND;VALUE=DATE-TIME:20210407T133000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/7
DESCRIPTION:Title: Wormholes and black hole microstates in AdS/CFT\nby Kristan Jensen (U
niversity of Victoria) as part of SISSA HEP seminars\n\n\nAbstract\nIt has
long been known that the coarse-grained approximation to the black hole d
ensity of states can be computed using classical Euclidean gravity. In thi
s talk I will argue for another entry in the dictionary between Euclidean
gravity and black hole physics\, namely that Euclidean wormholes describe
a coarse-grained approximation to the energy level statistics of black hol
e microstates. We do so by using the method of constrained instantons to o
btain an integral representation of wormhole amplitudes in Einstein gravit
y and in full-fledged AdS/CFT. These amplitudes are non-perturbative corre
ctions to the two-boundary problem in AdS quantum gravity. The full amplit
ude is likely UV sensitive\, dominated by small wormholes\, but it admits
an integral transformation with a macroscopic\, weakly curved saddle-point
approximation. The saddle is the "double cone" geometry of Saad\, Shenker
\, and Stanford\, with fixed moduli. In the boundary description this sadd
le appears to dominate a smeared version of the connected two-point functi
on of the black hole density of states\, and suggests level repulsion in t
he microstate spectrum. I will also discuss the stability of these wormhol
es to small fluctuations and to brane nucleation. Our results indicate a f
actorization paradox in AdS/CFT\, and I will discuss a potential mechanism
for understanding it.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Riccardo Rattazzi (EPFL\, Lausanne)
DTSTART;VALUE=DATE-TIME:20210421T123000Z
DTEND;VALUE=DATE-TIME:20210421T133000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/8
DESCRIPTION:Title: The quantum mechanics of a perfect fluid\nby Riccardo Rattazzi (EPFL\
, Lausanne) as part of SISSA HEP seminars\n\n\nAbstract\nFinite density sy
stems can be described by effective field theories with non-linearly reali
zed space-time symmetries\,\nwhose construction resembles that of the QCD
chiral lagrangian. Also based on that similarity\, one would expect the \n
construction to work equally well classically and quantum mechanically. Wh
ile that is true for superfluids and solids\, \none instead finds that for
genuine fluids things are made more complicated by the unusual dynamics o
f their transverse \nmodes\, which are not described by a Fock space. Foc
ussing on the incompressible limit in 2+1 dimensions\, I illustrate how a
consistent quantum mechanical description of a perfect fluid can be obtain
ed by using the known equivalence between the area preserving diffeomorfis
m group in 2D and $SU(N)$ with $N\\to \\infty$.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/8/
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BEGIN:VEVENT
SUMMARY:Gustavo Joaquin Turiaci (UCSB)
DTSTART;VALUE=DATE-TIME:20210505T150000Z
DTEND;VALUE=DATE-TIME:20210505T160000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/9
DESCRIPTION:Title: The black hole spectrum in (super)gravity\nby Gustavo Joaquin Turiaci
(UCSB) as part of SISSA HEP seminars\n\n\nAbstract\nAbstract: The talk wi
ll focus on the spectrum of near-extremal black holes in gravity and near-
BPS black holes in supergravity. We will study cases in asymptotically fou
r-dimensional flat space and three-dimensional Anti-de Sitter. This will b
e done by analyzing quantum effects near the horizon captured by an emerge
nt Jackiw-Teitelboim mode at low temperatures. This will allow us to syste
matically study questions such as the extremal degeneracy and the size of
the gap in the black hole spectrum\, which can be compared to some string
theory constructions.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Irene Valenzuela (Harvard)
DTSTART;VALUE=DATE-TIME:20210519T133000Z
DTEND;VALUE=DATE-TIME:20210519T143000Z
DTSTAMP;VALUE=DATE-TIME:20210514T204444Z
UID:SISSAHEP/10
DESCRIPTION:Title: A CFT Distance Conjecture\nby Irene Valenzuela (Harvard) as part of
SISSA HEP seminars\n\n\nAbstract\nWe formulate a series of conjectures rel
ating the geometry of conformal manifolds to the spectrum of local operato
rs in conformal field theories in d>2 spacetime dimensions. Our central co
njecture is that all theories at infinite distance in the Zamolodchikov me
tric possess an emergent higher-spin symmetry\, generated by an infinite t
ower of currents whose anomalous dimensions vanish exponentially in the di
stance. This is sustained by known data collected from the landscape of SC
FTs\, and yet it suggests a number of intriguing new properties. In the ho
lographic context our conjectures are related to the Distance Conjecture i
n the Swampland program. Interpreted gravitationally\, they imply that app
roaching infinite distance in moduli space at fixed AdS radius\, a tower o
f higher-spin fields becomes massless at an exponential rate that is bound
ed from below in Planck units. This relates to recent developments of the
Distance Conjecture in N=1 4d supergravity theories\, where higher spin fi
elds also play an essential role as the conjecture seems to follow from th
e universal presence of an axionic BPS string at every infinite field dist
ance limit.\n
LOCATION:https://researchseminars.org/talk/SISSAHEP/10/
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