During the semester we have a high energy seminar and a lunch seminar. In addition to these two seminars we participate in a joint theoretical high energy theory seminar in Newe Shalom. The joint seminar takes place on Tuesdays from 10:30 until 13:30 and includes two talks and lunch. This seminar is attended by the high energy groups of all the Israeli institutions and usually attracts a crowd of roughly twenty participants.

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` ` Sun Mon Tue Wed Thu Fri Sat Soumyadeep Chaudhuri 10:30 am Soumyadeep Chaudhuri Oct 22 @ 10:30 am – 11:30 am Title : Out of time ordered effective dynamics of a Brownian particle Abstract : In this talk I will present the out of time ordered dynamics of a Brownian particle interacting with a thermal bath. … Sergei Dubovsky 12:00 pm Sergei Dubovsky Oct 22 @ 12:00 pm – 1:00 pm Title: “Integrability from Confinement” Abstract: I will argue that high energy dynamics on the worldsheet of confining strings is integrable and illustrate this point using two examples. The first is a pure Yang—Mills theory in …

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Title : Out of time ordered effective dynamics of a Brownian particle

Abstract : In this talk I will present the out of time ordered dynamics of a Brownian particle interacting with a thermal bath. To illustrate the features of this effective dynamics, I will describe a simple toy model where the bath comprises of two sets of harmonic oscillators coupled nonlinearly to the Brownian particle. Beginning with a Schwinger-Keldysh effective action of the particle, I will demonstrate its duality with a stochastic theory governed by a non-linear Langevin equation. This Langevin dynamics or the equivalent Schwinger-Keldysh effective theory is, however, inadequate for determining the Out-of-Time-Order Correlators (OTOCs) of the particle.This limitation can be overcome by extending the particle’s effective theory to a path integral formalism defined on a contour with multiple time-folds. This extension introduces some new effective couplings which are determined by the bath’s OTOCs. The couplings in this OTO effective theory satisfy some constraints due to microscopic reversibility and thermality of the bath. I will show that, from the point of view of the Langevin dynamics, these constraints lead to a generalised fluctuation-dissipation relation between a non-Gaussianity in the noise distribution and a thermal jitter in the particle’s damping coefficient.

Title: “Integrability from Confinement”

Abstract:

I will argue that high energy dynamics on the worldsheet of confining strings is integrable and illustrate this point using two examples.

The first is a pure Yang—Mills theory in two spatial dimensions. There this logic allows one to obtain a prediction for quantum numbers

of all glueballs. I will present results of a dedicated lattice simulation which confirm this prediction. The second example is an adjoint QCD in one spatial dimension.

There this logic leads to a “zigzag model”—a remarkably simple novel integrable relativistic $N$-body system. I will prove the Liouville integrability

of the zigzag model by presenting an explicit construction of the corresponding conserved charges.

This model describes the $N$-particle subsector of a $Tbar{T}$-deformed massless fermion and

suggests a natural setting for constructing off-shell observables in $Tbar{T}$-deformed theories.

“Holographic order from modular chaos”

Title: Generalised Riemann Hypothesis, Random Time Series and Normal Distributions

Abstract: L functions based on Dirichlet characters are natural generalizations of the Riemann zeta function: they both have series representations and satisfy an Euler product representation, i.e. an infinite product taken over prime numbers. We address the Generalized Riemann Hypothesis relative to the non-trivial complex zeros of the Dirichlet L functions by studying the possibility to enlarge the original domain of convergence of their Euler product. This leads us to analyse the asymptotic behaviour of particular series on primes: although deterministic, these series have pronounced stochastic features which make them analogous to random time series. For non-principal characters, we show that, in view of the Dirichlet theorem on the equidistribution of reduced residue classes modulo q and the Lemke Oliver-Soundararajan result on the distribution of pairs of residues on consecutive primes, these series present a universal diffusive random walk behavior with critical exponent ½.

title: N=1 conformal dualities

abstract: We consider on one hand the possibility that a supersymmetric N = 1 conformal gauge theory has a strongly coupled locus on the conformal manifold at which a different, dual, conformal gauge theory becomes a good weakly coupled description. On the other hand we discuss the possibility that strongly coupled theories, e.g. SCFTs in class S, having exactly marginal N = 1 deformations admit a weakly coupled gauge theory description on some locus of the conformal manifold. We present a simple algorithm to search for such dualities and discuss several concrete examples. In particular we find conformal duals for N = 1 SQCD models with G2 gauge group and a model with SU(4) gauge group in terms of simple quiver gauge theories. We also find conformal weakly coupled quiver theory duals for a variety of class S theories: T4, R0,4, R2,5, and rank 2n Minahan-Nemeschansky E6 theories. Finally we derive conformal Lagrangians for four dimensional theories obtained by compactifying the E-string on genus g > 1 surface with zero flux. The pairs of dual Lagrangians at the weakly coupled loci have different symmetries which are broken on a general point of the conformal manifold. We match the dimensions of the conformal manifolds, symmetries on the generic locus of the conformal manifold, anomalies, and supersymmetric indices. The simplicity of the procedure suggests that such dualities are ubiquitous.

Title: Integrability and Renormalization under TT¯

Abstract: Smirnov and Zamolodchikov recently introduced a new class of two-dimensional quantum field theories, defined through a differential change of any existing theory by the determinant of the stress-tensor. From this TT¯ flow equation one can find a simple expression for both the energy spectrum and the S-matrix of the TT¯ deformed theories. Our goal is to find the renormalized Lagrangian of the TT¯ deformed theories. In the context of the TT¯ deformation of an integrable theory, the deformed theory is also integrable and, correspondingly, the S-matrix factorizes into two-to-two S-matrices. One may thus hope to be able to extract the renormalized Lagrangian from the S-matrix. We do this explicitly for the TT¯ deformation of a free massive scalar, to second order in the deformation parameter. Once one has the renormalized Lagrangian one can, in principle, compute all other observables, such as correlation functions. We briefly discuss this, as well as the relation between the renormalized Lagrangian, the TT¯ flow equation, and the S-matrix.