Seminar June 4: N. Seiberg

On June 4 we will have a seminar by

Nathan Seiberg (IAS Princeton)

Title: Continuum Quantum Field Theories for Fractons

Abstract: Starting with a lattice system at short distances, its long-distance behavior is captured by a continuum Quantum Field Theory (QFT). This description is universal, i.e. it is independent of most of the details of the microscopic system. Surprisingly, certain recently discovered lattice systems, and in particular models of fractons, seem to violate this general dogma. Motivated by this apparent contradiction, we will present exotic continuum QFTs that describe these systems. This talk will have a different emphasis than previous talks with the same title and abstract.

Meeting information:
4th of June at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/c15d10

You can watch the recording at
https://pandora.infn.it/public/7e4c79

Seminar May 28: S. Wolfram

On May 28 we will have a seminar by

Stephen Wolfram (Wolfram Research)

Title: A Surprisingly Promising Approach to the Fundamental Theory of Physics

Abstract:
What might an ultimate rule for physics—below space, time, particles, etc.—be like?  I had an idea about this 30 years ago, wrote about in 2002, and finally last fall decided to investigate it again … and to my great surprise realized that it actually looks as if it can work.  It has no intrinsic notion of space or time, but just consists in repeatedly (like 10^400 times) applying a very simple rule to abstract collections of elements and relations which can be thought of as forming a hypergraph.  With various assumptions the large-scale limit behaves like continuum space, shows Lorentz invariance, and reproduces the Einstein equations (including energy-momentum).  Different rewritings of the hypergraph define a multiway system, whose large-scale limit reproduces quantum mechanics, and in particular the path integral.  In the framework, general relativity and quantum mechanics are essentially the same theory, but applied to the spacetime causal graph as opposed to the multiway causal graph.  I’ll talk about the structure of the theory, some of its potential predictions, and (insofar as I understand them) its apparently close connections with popular recent mathematical physics approaches.

Meeting information:
28th of May at 18:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

You can watch the recording at
https://pandora.infn.it/public/28abf5

Seminar May 21: S. Schafer-Nameki

On May 21 we will have a seminar by

Sakura Schafer-Nameki (University of Oxford)

Title: Symmetries in 5d SCFTs and Gauge Theories

Abstract:
I will summarize recent progress in construction and studies of 5d N=1 gauge theories and their UV fixed points, with a focus on characterizing their global symmetries, both in the field theory and in the M-theory realization on a non-compact Calabi-Yau threefold.

Meeting information:
21st of May at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/fa094b

You can watch the recording at
https://pandora.infn.it/public/8250f0

Seminar May 7: M. Mariño

On May 7 we will have a seminar by

Marcos Mariño (University of Geneva)

Title: Resurgence, WKB and strings

Abstract:
The WKB method has played a fundamental role in the development of quantum mechanics. In the 1980s and 1990s, and largely under the influence of Ecalle’s theory of resurgence, it was upgraded to the exact (or complex) WKB method. More recently, developments in supersymmetric gauge theory and string theory have provided a new perspective on this venerable subject. In this talk I will review the basic ingredients of the exact WKB method and present new results inspired by gauge theory/string theory. I will show in particular that the work of Gaiotto-Moore-Neitzke on BPS states provides an elegant solution of the exact WKB method as applied to arbitrary polynomial potentials. I will also discuss some open problems in the subject.

Meeting information:
7th of May at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/e3a214

You can watch the recording at
https://pandora.infn.it/public/fd14c0

Seminar April 30: J. Maldacena

On April 30 we will have a seminar by

Juan Maldacena (IAS Princeton)

Title: The entropy of Hawking radiation and the information paradox

Abstract:
We will review recent progress on the black hole information paradox.
We start by reviewing some aspects of black hole thermodynamics.
Then we will introduce the formula for fine grained entropy of black holes. We apply it various examples. We then discuss how this formula computes the entropy of evaporating black holes as well as the entropy of Hawking radiation.

Meeting information:
30th of April at 16:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/2965e9

You can watch the recording at
https://pandora.infn.it/public/936a73

Seminar April 23: M. Lemos

On April 23 we will have a seminar by

Madalena Lemos (CERN)

Title: Surface defects in four-dimensional superconformal theories and chiral algebras

Abstract:
We study BPS surface defects in 4d superconformal field theories and show how symmetries constrain their anomaly coefficients. Focusing on N=(2,2) surface defects we review the protected subsector captured by a two-dimensional chiral algebra. We study the properties of the defect in this subsector and discuss how to compute the aforementioned anomaly coefficients.

Meeting information:
23rd of April at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/f8ed5f

You can watch the recording at
https://pandora.infn.it/public/e63cae

Seminar April 9: L. Tizzano

On April 9 we will have a seminar by

Luigi Tizzano (SCGP Stony Brook)

Title: Extremal Correlators and Random Matrix Theory

Abstract:
I will describe how the large charge limit of extremal correlators in N=2 superconformal field theories is captured by a dual description which is a random matrix model of the Wishart-Laguerre type. This gives a new analytic handle on the physics in some particular excited states. The random matrix model also admits a ‘t Hooft expansion in which the matrix is taken to be large and simultaneously the coupling is taken to zero. This explains why the extremal correlators of SU(2) gauge theory obey a nontrivial double scaling limit in states of large charge.

Meeting information:
9th of April at 14:30 Italian Time
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/52981e

You can watch the recording at
https://pandora.infn.it/public/b393bf

Seminar April 2: N. Mekareeya

On April 2 we will have a seminar by

Noppadol Mekareeya (INFN Milano Bicocca & Chulangokorn U. Bangkok)

Title: 3d S-fold SCFTs

Abstract:
A local SL(2,Z) transformation on the Type IIB brane configuration gives rise to an interesting class of 3d superconformal field theories, known as the S-fold SCFTs. One of the interesting features of such a theory is that, in general, it does not admit a conventional Lagrangian description. Nevertheless, it can be described by a quiver diagram with a link being a superconformal field theory, known as the T(U(N)) theory. In this talk, we discuss various interesting properties of the S-fold theories, including supersymmetry enhancement in the infrared as well as several interesting dualities.

Meeting information:
2nd of April at 14:30
Zoom Meeting https://zoom.us/j/198435430

Slides are available at
https://pandora.infn.it/public/3c8cc4

You can watch the recording at
https://pandora.infn.it/public/1929ad