Category: Seminar

On May 6 we will have a seminar by

Fabio Apruzzi (University of Oxford)

Title: Holography, 1-Form Symmetries and Confinement

Abstract: I will discuss confinement in 4d N = 1 SU(N) Super-Yang Mills (SYM) from holography, focusing on the 1-form symmetry and the holographic realization in terms of the Klebanov-Strassler solution. I will show how from the 5d consistent truncation it is possible to identify the topological couplings that determine the 1-form symmetry (and thus global forms of the gauge group) and its ’t Hooft anomalies. One of the topological couplings corresponds to a mixed 0-1-form symmetry anomaly, which is related to chiral symmetry breaking in the infrared (IR) vacuum. I will also show how to derive this anomaly from the Maldacena-Nunez solution and Little String Theory realizations of pure SYM. I will then discuss how other couplings in the 5d supergravity description of the IR Klebanov-Strassler solution lead to a 4d Topological Field Theory (TQFT) in the boundary, which saturates the mixed anomaly. 

Meeting information:
6th of May 14:30 Italian Time
Zoom Meeting https://l.infn.it/stringwebseminar

Slides are available at
https://pandora.infn.it/public/348d2f

On April 22 we will have a seminar by

Shlomo Razamat (Technion)

Title: SQCD and pairs of pants

Abstract: In this talk we will overview some approaches to study 4d strong coupling phenomena. In particular we will discuss a geometric re-interpretation of N=1 SQCD with special unitary gauge groups. We will argue that the 4d SU(M) SQCD in the middle of the conformal window can be engineered by compactifying certain 6d SCFTs on three punctured spheres.  We will also discuss in this context the interplay between simple geometric and group theoretic considerations and field theoretic strong coupling phenomena. We will show how many known and novel dualities and symmetry emergence phenomena of supersymmetric gauge theories, with  simple and semi-simple  special unitary gauge groups, are related to the Weyl group of $D_{6+2K}$.

Meeting information:
22nd of April 14:30 Italian Time
Zoom Meeting https://l.infn.it/stringwebseminar

You can watch the recording at
https://pandora.infn.it/public/43f4de

On April 8 we will have a seminar by

Fiona Seibold (ETH)

Title: Integrable deformations of superstrings

Abstract: I will give an overview of some recent developments concerning special types of integrable deformations that go under the name of eta (or Yang-Baxter) deformations. Focusing on eta-deformations of the AdS5xS5 superstring, I will explore the fate of Weyl invariance under these deformations and analyse the worldsheet scattering theory of the deformed models.

Meeting information:
8th of April 14:30 Italian Time
Zoom Meeting https://l.infn.it/stringwebseminar

Slides are available at
https://pandora.infn.it/public/28e194

You can watch the recording at
https://pandora.infn.it/public/e73a36

On March 11 we will have a seminar by

Lorenz Eberhardt (IAS)

Title: Summing over geometries in string theory

Abstract: I discuss the question how string theory achieves a sum over bulk geometries with fixed asymptotic boundary conditions. I analyze this problem with the help of the tensionless string on AdS3xS3xT4 (with one unit of NS-NS flux) that was recently understood to be dual to the symmetric orbifold of T4. I argue that large stringy corrections around a fixed background can be interpreted as different semiclassical geometries, thus making a sum over semi-classical geometries superfluous.

Meeting information:
11th of March 14:30 Italian Time
Zoom Meeting https://l.infn.it/stringwebseminar

Slides are available at
https://pandora.infn.it/public/95b99e

You can watch the recording at
https://pandora.infn.it/public/00cf45

On February 25 we will have a seminar by

Pietro Antonio Grassi (Università del Piemonte Orientale)

Title: The power of integral forms in supersymmetric field theories

Abstract: We present the power of a geometric framework for supergravity and supersymmetric theories solely based on differential calculus on supermanifolds. The relevant field theory Lagrangians are expressed by integral forms, ready to be integrated on the full supermanifold and automatically implementing the invariance  under super-diffeomorphisms. We show that different superspace formulations of a given theory arise from  the same action upon suitable choices of the integral forms. We also show the analogies with algebraic structures in string field theory and several new results. 

Meeting information:
25th of February 14:30 Italian Time
Zoom Meeting https://zoom.us/j/19843543

Slides are available at
https://pandora.infn.it/public/6b04f5

You can watch the recording at
https://pandora.infn.it/public/970e42

On February 11 we will have a seminar by

Nava Gaddam (Utrecht)

Title: The black hole eikonal and the information paradox

Abstract: In this talk, I will show that there is a remarkable phase of quantum gravity (which we will call the ‘black hole eikonal’ phase) where gravitational collision energies near the horizon satisfy E >> \gamma M_Pl, with \gamma = M_Pl/M_BH. I will argue that this regime captures gravitational scattering with impact parameters smaller than the Schwarzschild radius. Scattering amplitudes are unitary suggesting a resolution of the information paradox; I will sketch the explicit derivation of the 2-2 amplitude for massless scalars, non-perturbatively in \gamma. Owing to the low energies of collisions, there are no firewalls experienced by infalling observers. A consequence of these results is that the information paradox is an emergent one at low energies and does not require detailed ultra-violet physics for a resolution. 

Meeting information:
11th of February 14:30 Italian Time
Zoom Meeting https://zoom.us/j/19843543

You can watch the recording at
https://pandora.infn.it/public/be3ca2

On January 14 we will have a seminar by

Marc Henneaux (ULB & Collège de France)

Title: Asymptotic symmetries of electromagnetism and gravity: a Hamiltonian study

Abstract: The asymptotic symmetries of gravity and electromagnetism are remarkably rich.    The talk will explain the asymptotic structure of these theories in the asymptotically flat case by making central use of the Hamiltonian formalism.  In particular, how the relevant infinite-dimensional asymptotic symmetry groups emerge at spatial infinity will be discussed. Extensions to supergravity will be briefly touched upon.

Meeting information:
14th of January at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/19843543

Slides are available at
https://pandora.infn.it/public/c8b1b7

You can watch the recording at
https://pandora.infn.it/public/06173b

On December 10 we will have a seminar by

Julian Sonner (University of Geneva)

Title: Causal symmetry breaking: the EFT of quantum chaos

Abstract:

Quantum chaotic systems are often defined via the assertion that their spectral statistics coincides with, or is well approximated by, random matrix theory. In this talk I will explain how the universal content of random matrix theory emerges as the consequence of a simple symmetry-breaking principle and its associated Goldstone modes. This approach gives a natural way to identify wormhole-like correlations, even for individual theories.
I will also discuss how to extend the Goldstone effective-field-theory approach to study operator correlation functions, and present some thoughts on how to understand causal symmetry breaking in holographic bulk gravity.

Meeting information:
10th of December at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

You can watch the recording at
https://pandora.infn.it/public/0585a8

On November 26 we will have a seminar by

Paul Townsend (Cambridge U., DAMTP)

Title: Interacting alternatives to Maxwell’s equations preserving
conformal and duality invariance

Abstract:
The source-free Maxwell’s equations are both conformal invariant and
invariant under an SO(2) electromagnetic duality group. It is commonly
thought that these conditions imply their uniqueness. However, there are
two interacting electrodynamics theories with the same field content and
all the symmetries of Maxwell’s equations. One was found in 1983 by
Bialynicki-Birula from a strong-field limit of Born-Infeld theory; it has
an enhanced Sl(2;R)-duality invariance.  The other, dubbed “ModMax”, was
found very recently from a weak-field limit of a ‘generalized’ Born-Infeld
theory; it has a dimensionless coupling constant and reduces to Maxwell
for zero coupling. This talk will review the main features of both
Bialynicki-Birula and ModMax electrodynamics.

Meeting information:
26th of November at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/cf0ae7

You can watch the recording at
https://pandora.infn.it/public/35895c

On November 12 we will have a seminar by

Razvan Gurau (Heidelberg University)

Title: Random Tensors, from random geometry to conformal field theory

Abstract: In this talk I will briefly review the theory of Random Tensors. In the limit of large size (large N), random tensors exhibit a new “melonic” limit, simpler than the planar limit of random matrices but richer than the one of random vectors. This “not too complicated but not too trivial” situation is ideal for analytic computations. I will then discuss some applications of random tensors to random geometry and conformal field theory.

Meeting information:
12th of November at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/c8c4e2

You can watch the recording at
https://pandora.infn.it/public/d2610c