Events Archive

IAS HET Seminar | Lance Dixon, Stanford University| "Scattering Amplitudes in Maximally Supersymmetric Gauge Theory and a New Duality" | Wolfensohn Hall & Zoom
Mon, May 2, 2022, 2:30 pm2:30 pm

Scattering amplitudes are the arena where quantum field theory directly meets collider experiments.  An excellent model for scattering in QCD is provided by N=4 super-Yang-Mills theory, particularly in the planar limit of a large number of colors, where the theory becomes integrable, and amplitudes become dual to light-like polygonal Wilson…

POSTPONED!! IAS HET Seminar - Friday, April 22 - 1:45 PM - Wolfensohn Hall & Zoom - "Quantum Error Correction in SYK and Bulk Emergence" - Adam Levine, Member, School of Natural Sciences, IAS
Fri, Apr 29, 2022, 1:45 pm1:45 pm



We will discuss the price of the quantum error correcting codes, defined as the number of physical qubits needed to reconstruct whether a given operator has been acted upon the thermal state or not. By thinking about reconstruction via quantum teleportation…

IAS HET Seminar - Friday, April 22 - 1:45 PM - Wolfensohn Hall & Zoom - "Localized Collisions and the Black Hole Interior" - Felix Haehl, IAS
Fri, Apr 22, 2022, 1:45 pm1:45 pm

We study collisions of localized shockwaves behind the horizon of the eternal AdS black hole. We give a holographic boundary description in terms of the overlap of two growing perturbations in a shared quantum circuit. Due to a competition between different physical effects, the circuit analysis shows dependence on the transverse locations and…

IAS HET Seminar | Amit Sever, Tel-Aviv University| “"Line Operators in Chern-Simons-Matter Theories and Bosonization in Three Dimensions” | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Mon, Apr 18, 2022, 2:30 pm2:30 pm

We study Chern-Simons theories at large N with either bosonic or fermionic matter in the fundamental representation. The most fundamental operators in these theories are mesonic line operators, the simplest example being Wilson lines ending on fundamentals. We classify the conformal line operators along an arbitrary smooth path as well as the…

HET Seminar | John Cardy, University of California, Berkeley | “TTbar-deformed modula” | Via Zoom
Mon, Apr 11, 2022, 2:30 pm2:30 pm

Certain objects of conformal field theory, for example partition functions on the rectangle and the torus, and one-point functions on the torus, are either invariant or transform simply under the modular group, properties which should be preserved under the TTbar deformation. The formulation and proof of this statement in fact extends to more…

IAS HET Seminar | Hong Liu, Massachusetts Institute of Technology| “"Emergent Times in Holography” | Via Zoom
Mon, Apr 4, 2022, 2:30 pm2:30 pm

We discuss emergent type III1 von Neumann algebraic structures in the large N limit of certain class of quantum field theories. We show that this is important for understanding various aspects of bulk physics in the AdS/CFT duality, including explicit boundary constructions of Kruskal-like time evolution in an eternal black hole, boundary…

IAS HET Seminar | Javier Fuentes, University of Granada| “Following the Footprints of the B-physics Anomalies” | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Mon, Mar 28, 2022, 2:30 pm2:30 pm

Recent B-meson data show a reinforced set of deviations from the Standard Model predictions, pointing to violations of lepton flavor universality. I will critically review these data and discuss their theoretical interpretation, including their possible connection to the hierarchical pattern of fermions masses and mixing angles. To this end, I…

IAS HET Seminar | Matthew Heydeman, Member, School of Natural Sciences, IAS| “Nearly BPS Black Holes in AdS5 and their Spectrum in N=4 SYM” | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Fri, Mar 25, 2022, 1:45 pm1:45 pm

In this talk, we will discuss quantum corrections in the gravitational path integral around nearly 1/16-BPS black holes in asymptotically AdS5 x S5 space, dual to heavy operators in N=4 SYM. We argue these quantum corrections come from a version of the N=2 super-Schwarzian theory which captures the breaking of the SU(1,1|1) near horizon…

HET Seminar | Julio Parra-Martinez , Caltech | “Causality constraints on corrections to Einstein gravity” | PCTS Room 407
Mon, Mar 21, 2022, 2:30 pm2:30 pm

We study constraints from causality and unitarity on 2→2 graviton scattering in four-dimensional weakly-coupled effective field theories. Together, causality and unitarity imply dispersion relations that connect low-energy observables to high-energy data. Using such dispersion relations, we derive two-sided bounds on gravitational Wilson…

IAS HET Seminar | Anatoly Dymarsky, University of Kentucky & Skoltech | "Codes and Conformal Field Theories" | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Mon, Mar 14, 2022, 2:30 pm2:30 pm

I will review recent progress connecting (quantum) codes with two-dimensional conformal field theories of the Narain type. In the first part of the talk I will show how codes can be used to construct CFTs with large spectral gap. In the second part I will construct a map from a large class of rational Narain CFTs to quantum stabilizer codes.

IAS HET Seminar | Giulio Salvatori, Member, School of Natural Sciences, IAS| “Scattering Amplitudes, Positive Geometries and Surfaces” | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Fri, Mar 11, 2022, 1:45 pm1:45 pm

In recent years we have witnessed the emergence of a novel description for the physics of scattering amplitudes at the heart of which are mathematical structures called Positive Geometries, which loosely speaking are generalizations of polytopes having the crucial feature of encoding in their boundaries the singularity structure of…

HET Seminar | Beatrix Muhlmann, McGill University | “The semiclassical gravitational path integral and random matrices” | Via Zoom
Mon, Feb 21, 2022, 2:30 pm2:30 pm

According to Gibbons and Hawking the entropy of a dS universe is encoded in the Euclidean gravitational path integral over compact manifolds with dominant sphere saddle. In this talk I will report on recent work in which we explicitly calculate this gravitational path integral in two spacetime dimensions. Whereas the Euclidean two-dimensional…

HET Seminar |Justin Kaidi , Stony Brook University | “Kramers-Wannier-like duality defects in (3+1)d gauge theories” | Via Zoom
Fri, Feb 18, 2022, 1:45 pm1:45 pm

I will introduce a class of non-invertible topological defects in (3+1)d gauge theories whose fusion rules are the higher-dimensional analogs of those of the Kramers-Wannier defect in the (1+1)d critical Ising model. As in the lower-dimensional case, the presence of such non-invertible defects implies self-duality under a particular gauging of…

HET Seminar | Sabrina Gonzalez Pasterski, Princeton University | “The Celestial Almanac” | PCTS (Room 407) & Zoom
Mon, Feb 14, 2022, 2:30 pm2:30 pm

We start by revisiting the task of constructing a holographic dual to quantum gravity in asymptotically flat spacetimes. Upon recasting the S-matrix in terms of data at the conformal boundary, we see that the two standard approaches amount to slicing up the bulk and boundary in different ways.

The Celestial Hologram organizes…

IAS HET Seminar | Igor Klebanov, Princeton University; Distinguished Visiting Professor, School of Natural Sciences, IAS | "O(N), Sp(2M), and OSp(1|2M) Models" | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Fri, Feb 11, 2022, 1:45 pm1:45 pm


The upper critical dimension of the O(N) vector model is well-known to be 4. In dimension 4-epsilon it is described by the Wilson-Fisher IR fixed point of the O(N) invariant scalar field theory with a small positive quartic coupling. Above 4 dimensions, this theory is non-renormalizable, but in 4+epsilon dimensions it…

IAS HET Seminar | Kevin Costello, Perimeter Institute | “Scattering Amplitudes in Gauge Theory as Chiral Algebra Correlators” | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Mon, Feb 7, 2022, 2:30 pm2:30 pm

I will report on my recent work with Natalie Paquette, where we derive expressions for form factors and scattering amplitudes of gauge theory as correlators of a chiral algebra.  The chiral algebra is closely related to algebras appearing in the celestial holography program.



IAS HET Seminar | Shai Chester, Weizmann Institute of Science | "Bootstrapping N = 4 super-Yang-Mills on the conformal manifold" | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Mon, Nov 15, 2021, 2:30 pm2:30 pm

Abstract:  We study the = 4 SYM stress tensor multiplet 4-point function for any value of the complexified coupling tau, and in principle any gauge group (we focus on SU(2) and SU(3) for simplicity). By combining non-perturbative constraints from the numerical bootstrap with two exact constraints from supersymmetric localization, we…

IAS HET Seminar | Ahsan Z Khan, Member, School of Natural Sciences, IAS | "TBA" | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Fri, Nov 12, 2021, 1:45 pm1:45 pm
The Universe from a single Particle - Michael Freedman - Microsoft Q
Mon, Nov 1, 2021, 4:30 pm4:30 pm

I will explore a toy model for our universe in which spontaneous symmetry breaking – acting on the level of operators (not states) - can produce the interacting physics we see about us from the simpler, single particle, quantum mechanics we study as undergraduates. Based on joint work with Modj Shokrian Zini, see arXiv:2011.05917 and arXiv:2108…

IAS HET Seminar | Venkatesa Chandrasekaran, Member, School of Natural Sciences, IAS | "The Area Operator in Gravity and Holography" | Wolfensohn Hall (behind Bloomberg Hall) & on Zoom
Fri, Oct 29, 2021, 1:45 pm1:45 pm

Abstract:  The area operator plays a central role in our understanding of holography and black hole thermodynamics. In this talk I will discuss a formulation of the area operator at the level of classical gravity, the “kink transform”, which defines a notion of a half-sided boost of gravitational initial data. I will show that it satisfies the…