INFN Strings Web Seminars

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

On October 29 we will have a seminar by

Alberto Zaffaroni (Università di Milano Bicocca)

Title: Universal black holes in AdS

Abstract:
In this talk I discuss a universal microscopic counting for AdS black holes that arise as solutions of the half-maximal gauged supergravity in four and five dimensions. These solutions can be embedded in all AdS M-theory and type II string backgrounds with sixteen supercharges and provide an infinite set of examples dual to N = 2 and N = 4 conformal field theories in four and three dimensions, respectively.

Meeting information:
29th of October at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/f8e83e

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

On October 1st we will have a seminar by

Alexander Zhiboedov (CERN)

Title: Conformal Bootstrap in Mellin Space

Abstract:
I will talk about recent progress in analytic approaches to the conformal bootstrap. I will introduce Mellin space as a convenient tool to perform both perturbative and nonperturbative computations in conformal field theories. I will discuss dispersion relations in Mellin space, the sum rules that they lead to, and applications thereof. These include the Wilson-Fisher model in d=4-eps dimensions and holographic computations. I will also talk about generalization of these techniques to finite temperatures.

Meeting information:
1st of October at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/f3a2e1

You can watch the recording at
https://pandora.infn.it/public/21c6db

On June 25 we will have a seminar by

Charlotte Kristjansen (Niels Bohr Institute)

Title: News on domain walls and integrability in N=4 SYM.

Abstract:
Domain walls in N=4 SYM theory separating regions with different vevs for the scalar fields allow us to study versions of AdS/CFT where supersymmetry is either partially or completely broken and where boundary integrability might or might not be present. We review the present status of this line of research paying particular attention to novel results on integrability beyond the scalar sector, at higher loops and for the non-supersymmetric D3-D7 probe brane set-up.

Meeting information:
25th of June at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/9e97f9

You can watch the recording at
https://pandora.infn.it/public/cdc69a

On June 18 we will have a seminar by

Luis Fernando Alday (Oxford)

Title: 6d (2,0) correlators and quantum M-theory

Abstract:
We study holographic correlators in maximally super-symmetric conformal field theories. This includes the 6d (2,0) theory, where our computation is dual to graviton scattering in weakly coupled M-theory on AdS₇ × S⁴. Although the theory is non-Lagrangian, analytic bootstrap techniques allow us to make computations to one loop order. The flat space limit of our results exactly reproduces the 11d M-theory S-matrix in flat space.

Meeting information:
18th of June at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/aabe3f

You can watch the recording at
https://pandora.infn.it/public/6cb0c1

On June 11 we will have a seminar by

Niels Obers (NORDITA)

Title: Non-relativistic gravity and strings

Abstract: I will start by motivating the recent interest in non-relativistic gravity and strings. These build on recent advances and generalizations of Newton-Cartan geometry, originally introduced by Cartan to geometrize Newtonian gravity. I will then present an action principle for non-relativistic gravity and its coupling to matter, including its Newtonian limit. This requires a new notion of NC geometry, which  naturally arises in a covariant 1/c expansion of general relativity, with c being the speed of light. The corresponding non-relativistic truncation of general relativity goes beyond Newtonian gravity and is able to correctly describe gravitational time dilation. Finally, I will discuss how non-relativistic geometry appears in connection to non-relativistic strings and limits of the AdS/CFT correspondence. 

Meeting information:
11th of June at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/bd2da0

You can watch the recording at
https://pandora.infn.it/public/d05d44