Past Events
Group Meeting Talk: Large N Phase Transitions and Small AdS-Schwarzschild Black Holes
2020-06-22Large N Phase Transitions and Small AdS-Schwarzschild Black Holes
Speaker: Sudip Ghosh
Abstract: We will discuss aspects of small AdS-Schwarzschild Black Holes in the context of the AdS/CFT correspondence. In particular we will consider issues related to dynamical instabilities of small black holes and their dual interpretation in the boundary gauge theory at large N.
Journal club seminar: Extended TQFT
2020-06-17Title: Extended TQFT
Abstract: This talk is the continuation of my TQFT discussion from last week. I am going to discuss the extended TQFT as an open-closed strings following the nice paper by Aaron D. Lauda, Hendryk Pfeiffer "Open-closed strings: Two-dimensional extended TQFTs and Frobenius algebras". After that I am going to discuss 2-categories approach and compare it with asymptotic symmetries and edge modes.
QG group meeting: boundary locality vs. higher-spin symmetry
2020-06-15QG group meeting.
Speaker: Yasha Neiman
Title: "Boundary locality vs. higher-spin symmetry"
Journal club seminar:Strings from Massive Higher Spins: The Asymptotic Uniqueness of the Veneziano Amplitude
2020-06-10Title: Strings from Massive Higher Spins: The Asymptotic Uniqueness of the Veneziano Amplitude
Abstract: We are going to discuss the recent paper by Simon Caron-Huot, Zohar Komargodski, Amit Sever and Alexander Zhiboedov "Strings from Massive Higher Spins: The Asymptotic Uniqueness of the Veneziano Amplitude". Dorian Weissman will be leading the discussion.
QG group meeting: TQFT and Asymptotic Symmetries
2020-06-08Title : TQFT and Asymptotic symmetries
Speaker: Vyacheslav Lysov
Abstract: I will provide an introduction to topological quantum field theories (TQFT) and their generalization - Extended TQFT. Using the TQFT framework I am going to discuss the behaviour of Hilbert spaces, associated to the boundary components, under the gluing.
Novel Perspectives in String Phenomenology
2020-06-01I will review the structure of the fermionic Z2xZ2 orbifolds that produced a large space of phenomenological three generation models. I will discuss the trial and error old school method that gave rise to the first known string derived MSSM models, as well as the more modern classification methods that enables the analysis of large spaces of vacua and extraction of some of the global properties underlying them, e.g. spinor--vector duality. I will discuss a new direction of research that was initiated over the past year. Since the mid-eighties it is known that in addition to the ten dimensional tachyon free heterotic-string vacua there exist tachyonic ten dimensional vacua. In the supersymmetric and non-supersymmetric tachyon free cases the ten dimensional tachyon are projected out by the same projection. I will discuss the construction of phenomenological tachyon free models starting from the tachyonic 10D vacua and their particular features.
Domain Walls of N=1, D=4 Super Yang-Mills Theory
2020-05-25Title: How Domain Walls of N=1, D=4 SYM look like
Speaker: Dmitri Sorokin, University of Padua, Italy
Abstract: We review main features of the pure N=1, D=4 SYM with the gauge group SU(N) and its effective description by the Veneziano-Yankielowicz generalized sigma-model. We then indicate that the construction of BPS domain walls interpolating between different SYM vacua requires the presence of a dynamical membrane source. We will show how such a membrane is coupled to the SYM and present the explicit form of BPS domain walls which it creates in the Veneziano-Yankielowicz effective theory. In particular, we will describe 1/2 BPS domain wall configurations with |k| less than or equal to N/3, where k is the membrane charge that sets the "distance" between two distinct SUSY vacua.
Reductionism, physics, mathematics and the mind
2020-05-22General-audience geek-out Zoom talk.
Speaker: Yasha Neiman.
Title: "Reductionism, physics, mathematics and the mind".
Quantization of folded strings in non-critical dimensions
2020-05-18Title: Quantization of folded strings in non-critical dimensions
Speaker: Dorin Weissmann
Abstract: I will talk about some problems that arise when attempting to quantize rotating strings semiclassically, in the critical and non-critical dimensions. The problems are divergences associated with folding points in the string. A rotating closed string is a basic system that suffers from this problem, and I show how we deal with it by treating the fold as a boundary and placing mass terms there. Based on an upcoming paper with J. Sonnenschein.
The spiritual art of Calculus and the union of Heaven and Earth
2020-05-08Seminar for general audience, about mankind's discovery of magic.
Speaker: Yasha Neiman.
Title: "The spiritual art of Calculus and the union of Heaven and Earth".