Events Archive

IAS HET Seminar | Erez Urbach, Weizmann Institute of Science | “The Black Hole/String Transition in anti de Sitter Space” |Bloomberg Lecture Hall (IAS) & Zoom
Mon, Oct 9, 2023, 2:30 pm2:30 pm

 String stars, or Horowitz-Polchinski solutions, are string theory saddles with normalizable condensates of thermal-winding strings. In the past, string stars were offered as a possible description of stringy (Euclidean) black holes in asymptotically flat spacetime, close to the Hagedorn…

IAS HET Seminar | Michael Borinsky, ETH Zurich | “The Dark-Matter Problem of the Moduli Space of Curves and its (partial) Tropical Solution” | Wolfensohn Hall (IAS) & Zoom
Fri, Oct 6, 2023, 2:30 pm2:30 pm

The moduli space of curves, M_g, is an object of pivotal interest in mathematics and theoretical physics. Even though it has been studied with tremendous effort, little is known about its topology. For instance, the total dimension of the cohomology of M_g grows quickly with g, but the known constructions for cohomology classes only account for…

HET Seminar |Hirosi Ooguri, Caltech & Kavli IPMU| “Symmetry Resolution at High Energy” | IAS
Mon, Oct 2, 2023, 2:30 pm3:30 pm

The density of states of a unitary conformal field theory is known to have a universal behavior at high energy. In two dimensions, this behavior is described by the Cardy formula. If the theory has symmetry, it is interesting to understand the symmetry resolution, namely the decomposition of its Hilbert space into irreducible representations of…

HET Seminar |Silviu Pufu, Princeton | “ Two approaches to adjoint QCD_2” | PCTS
Fri, Sep 29, 2023, 11:00 am11:00 am

 In this talk, I will discuss the 2d SU(N) gauge theory coupled to an adjoint Majorana fermion using two approaches.  First, I will describe the computation of the spectrum at finite N using Discretized Light-Cone Quantization.  Then, for the N=2 case, I will introduce a Hamiltonian lattice model that can also be used to compute…

IAS HET Seminar | David E. Kaplan, Johns Hopkins University | “Non-Linear Quantum Mechanics” | Bloomberg Lecture Hall (IAS) & Zoom
Mon, Sep 25, 2023, 2:30 pm2:30 pm

We add non-linear and state-dependent terms to the Hamiltonian of quantum field theory. The resulting low-energy theory, non-linear quantum mechanics, is causal, preserves probability and permits a consistent description of the process of measurement. We explore the consequences of such terms and show that non-linear…

HET Seminar | Valentin Reys, IPhT, Saclay | “Precision holography for (non-)susy observables” | PCTS
Fri, Sep 22, 2023, 11:00 am11:00 am

I will review recent progress in understanding perturbative corrections to the large N limit of various observables in holographic 3d SCFTs. For supersymmetric observables, these corrections are obtained from supersymmetric localization and can be used to infer the value of higher-derivative couplings in the dual…

HET Seminar |Tom Shachar, The Racah Institute of Physics | “ RG flows on two-dimensional spherical defects” | PCTS
Tue, Sep 19, 2023, 2:00 pm2:00 pm

The irreversibility of RG flows on conformal defects has been a subject of great interest recently. In this talk I will present an entropy function defined on 2D spherical defects, interpolating between the defect anomaly coefficient at the fixed points. We reproduce the IR sum-rule proving irreversibility and show…

HET Seminar |Christian Ferko, UC Davis | “Three Perspectives on Two Throats” | PCTS
Mon, Sep 18, 2023, 2:30 pm2:30 pm

For certain black hole spacetimes, we are fortunate to have three complementary views of the same physics: (1) the low-energy gravity theory on the spacetime M, (2) worldsheet string theory with target space M, and (3) a holographic description living on the boundary of M. In this talk, I describe ongoing efforts to compare these perspectives…

IAS HET Seminar | Aidan Herderschee, Member, School of Natural Sciences, IAS | “The Next-to-Leading Order Scattering Waveform from Amplitudes” |Bloomberg Lecture Hall (IAS) & Zoom
Fri, Sep 15, 2023, 11:00 am11:00 am

 

I will showcase the computation of the next-to-leading order scattering waveform in classical gravity using amplitude techniques. I will first give an overview of how to compute generic classical observables in gravity using scattering amplitude techniques in the KMOC formalism. In particular, I will…

IAS HET Seminar | Leonard Susskind, Stanford University| “"DSSYK∞ and its Possible Dual Relation to JT-de Sitter Space"” | Zoom
Thu, Sep 14, 2023, 11:00 am11:00 am

I will explain my reasons for thinking that the double-scaled SYK theory at infinite temperature is a theory of de Sitter space.

 

HET Seminar |Slava Rychkov (IHES) | “ Interacting fixed points without conformal invariance” | PCTS
Fri, Sep 8, 2023, 11:00 am12:00 pm

I will start with some comments about the theoretical and experimental status of conformal invariance in critical phenomena, first proposed by A. Polyakov in 1970. I will then focus on a couple of experimentally significant models of statistical physics (ferromagnets in presence of strong dipolar forces, fluctuating…

IAS HET Seminar | Georgi Dvali, Max-Planck-Institute for Physics| “Saturons and Their Role as Dark Matter” | Bloomberg Lecture Hall & Zoom
Fri, Jun 2, 2023, 1:45 pm1:45 pm

"Saturons" are macroscopic objects that exhibit maximal micristate degeneracy within the validity of a given quantum  field theoretic description.  Due to this feature, saturons and black holes belong to the same universality class with common key properties.  However, as opposed to black holes, saturons…

IAS HET Seminar | Gustavo Joaquin Turiaci, Member, School of Natural Sciences, IAS| “Random Matrix Universality for Black Holes in Supergravity” | Bloomberg Lecture Hall & Zoom
Fri, May 19, 2023, 1:45 pm3:00 pm

Some aspects of the black hole spectrum, coming from spacetime wormhole contributions, can be modeled by a random matrix ensemble. It is important to understand the appropriate ensemble for theories with extended supersymmetry, since for example this is the case for systems with known gravity duals coming from string…

IAS HET Seminar | Matthew Hastings, Microsoft| “The Sum-of-Squares for Fermionic Systems, and the SYK Model” | Zoom Only
Mon, May 15, 2023, 2:30 pm2:30 pm

Perhaps the most important problem in physics or quantum chemistry is to determine properties of the ground state of an interacting system of fermions.  As a quantum mechanical problem, there may be no efficient classical witness to the ground state energy, or even to an approximation of that energy.  A…

HET Seminar |Lorenz Eberhardt, Member, School of Natural Sciences, IAS| “Evaluating one-loop string amplitudes” | PCTS & Zoom
Fri, May 12, 2023, 1:45 pm1:45 pm

 I will explain recent work with S. Mizera in which we give explicit evaluations of one-loop open string amplitudes at finite alpha’. Our method involves various deformations of the contour integral over the modular parameter. We directly verify that the one-loop string amplitude satisfies unitarity constraints. I…

IAS HET Seminar | Savas Dimopoulos, SITP, Stanford University| “The Cosmic Neutrino Background (CνB): Its Distribution on the Surface of the Earth and its Manipulation by Laboratory-Scale Diffraction Gratings” | Bloomberg Lecture Hall & Zoom
Mon, May 8, 2023, 2:30 pm2:30 pm

The CνB is a cosmological relic analogous to the CMB, and contains information about the universe before it was one-second-old. Reflection of relic neutrinos from the surface of the Earth creates a significant local neutrino-antineutrino asymmetry in a shell seven meters thick around the Earth's surface. This asymmetry…

IAS HET Seminar | Matthew Heydeman, Member, School of Natural Sciences, IAS| “Supersymmetric Black Holes, Defects, and Phase Transitions” | Bloomberg Lecture Hall & Zoom
Fri, May 5, 2023, 1:45 pm3:00 pm

Supersymmetric black holes in Anti de-Sitter space have recently been shown to have a large number of exactly degenerate microstates. In the first part of the talk, we will review how AdS5 black hole microstates may be reliably counted in the dual N=4 SYM theory using the superconformal index, a partition function preserving 1/16-supersymmetry…

HET Seminar |Howard Georgi, Harvard| “Fun with n-flavor Schwinger models” | PCTS & Zoom
Fri, Apr 28, 2023, 1:45 pm1:45 pm

I will describe the correlators of fermion bilinears in the n-flavor massless Schwinger model. These are exactly calculable generalized free theories. For n > 1, there is a massive particle and a conformal sector. I have argued that in the n = 2 theory, very special mass terms can be added to introduce interactions…

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HET Seminar |Yiyang Jia, Weizmann Institute of Science| “Parisi's hypercube, Fock-space frustration and NAdS$_2$/NCFT$_1$ holography” | PCTS & Zoom
Thu, Apr 27, 2023, 2:30 pm2:30 pm

We consider a model of Parisi where a single particle hops on an infinite-dimensional hypercube, under the influence of a uniform but disordered magnetic flux.  We reinterpret the hypercube as the Fock-space graph of a many-body Hamiltonian, and the flux as a frustration of the return amplitudes in Fock space. We…