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Web seminars launch and calendar

In view of the ongoing Coronavirus pandemic we have decided to start an on-line series to continue our scientific exchange in spite of the adversities.

Ordinarily seminar will take place on Thursdays at 14:30 Italian time.

The seminars are organised through Zoom meetings, and it is possible to join through the link
https://zoom.us/j/198435430
(Meeting ID: 198 435 430 )

You can subscribe to our (Google) calendar using this link:
https://bit.ly/2y5NzNZ

Alessandro and Domenico

Seminar June 25: C. Kristjansen

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

Seminar June 18: L.F. Alday

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

Seminar June 11: N. Obers

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

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