# Events Archive

## High Energy Theory Seminar

### HET Seminar | Matteo Lotito, UCincinnati | "Uncovering flavor of N SCFTs through geometry" | Jadwin A06

Tue, Nov 7, 2017, 1:30 pm

I will present a novel classification of 4d rank-1N Superconformal Field Theories (SCFTs), based purely on topological data.

We study the low energy effective theory of N SCFTs exploiting the structure of the moduli spaces of vacua these theories possess.

Speaker(s):

### HET Seminar | David Lowe, Brown | "Black hole holography and mean field evolution" | PCTS Seminar Room

Mon, Nov 6, 2017, 2:30 pm

Holographic theories representing black holes are expected to exhibit quantum chaos. If the laws of quantum mechanics are expected to hold for observers inside such black holes, then such holographic theories must have a mean field approximation valid for typical black hole states, and for timescales approaching the scrambling time.

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### HET Seminar at IAS | Kyle Cranmer, NYU | “What does the Revolution in Artificial Intelligence Mean for Physics?”

Mon, Oct 30, 2017, 2:30 pm

There is no doubt that there is a revolution going on in machine learning and artificial intelligence, but what does it mean for physics? Is it all hype, or will it transform the way we think about and do physics?

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### HET Seminar | Emil Akhmedov, ITEP Moscow | "Surprises of quantization in de Sitter space" | PCTS Sem Rm

Mon, Oct 30, 2017, 11:00 am

I will talk about loop infrared effects in de Sitter QFT. Namely about their types, physical meaning and origin and also about their resumation.

Speaker(s):

### HET Seminar | Hong Liu, MIT | "A hydrodynamical theory for quantum many-body chaos" | PCTS Seminar Room

Fri, Oct 27, 2017, 1:45 pm

Recently there has been progress on characterizing chaos in quantum many-body systems by studying commutators

of generic few-body operators in a thermal state. In this talk we introduce an effective theory, in fact a hydrodynamical theory,

to describe the "butterfly effect" exhibited by these commutators.

Speaker(s):

### HET Seminar | Fabio Sanches, UC Berkeley | "Bulk locality from subregion duality" | PCTS Seminar Room

Tue, Oct 24, 2017, 4:00 pm

I will explain a procedure to determine if a given nonlocal operator in a large-N holographic CFT is dual to a local bulk operator on the geometry associated with a particular code subspace of the CFT. This procedure does not presuppose knowledge of the bulk geometry.

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### HET Seminar | Eduardo Teste, Instituto Balseiro Centro Atomico Bariloche | "Entropic A theorem and the Markov property of the vacuum" | PCTS Seminar Room

Mon, Oct 23, 2017, 2:30 pm

A state is said to be Markovian if it fulfil the important condition of saturating the Strong Subadditivity inequality. I will show how the vacuum state of any relativistic QFT is a Markov state when reduced to certain geometric regions of spacetime.

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### HET Seminar at IAS | Anna Karlsson, Member, School of Natural Sciences, IAS | "TBA"

Fri, Oct 20, 2017, 1:45 pm
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### HET Seminar | Alexander Vilenkin, Tufts U. | "Black holes from cosmic inflation" | PCTS Seminar Rm

Mon, Oct 16, 2017, 2:30 pm

Spherical domain walls and vacuum bubbles can spontaneously nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the walls and/or bubbles form black holes with a wide spectrum of masses.  For some parameter values, the black holes can serve as dark matter or as seeds for supermassive black holes at...

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### HET Seminar | Nima Lashkari, MIT | "Diffeomorphisms and RG monotones" | PCTS Seminar Rm

Fri, Oct 13, 2017, 1:45 pm

I discuss the amount of information in quantum field theory states reduced to a region, that cannot be recovered from its subregion density matrices. One can reconstruct the density matrix from its subregions using two approaches: scaling maps and recovery maps. The vacuum of a conformal field theory is a quantum Markov state and the fixed...

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### Special HET Seminar at IAS | Piljin Yi, Korean Institute for Advanced Study | “Indices, Localization, Rational Invariants, and H-Saddles”

Tue, Oct 10, 2017, 1:45 pm

In recent years, varieties of index-like quantitites have been computed by exact path integral, a.k.a. the localization. For gauge theories, the computations reduces to contour integrals, famously riddled with subtleties.

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### HET Seminar at IAS | Thomas Hartman, Cornell University | “Causality and the Length Operator”

Mon, Oct 9, 2017, 2:30 pm

Causality in quantum field theory is encoded in the averaged null energy condition. I will describe how, in large-N CFTs, this energy condition is replaced by a stronger inequality involving the spectrum of the length operator in the dual AdS.

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### Special HET Seminar at IAS | Irene Valenzuela, Max-Planck-Institut für Physik | "Contraints on Particle Physics and Inflation from Quantum Gravity Conjectures"

Thu, Oct 5, 2017, 1:45 pm

Consistency with quantum gravity can have significant consequences on low energy physics. For instance, using the Weak Gravity Conjecture, it has been recently argued by Ooguri and Vafa that non supersymmetric stable AdS vacua are incompatible with quantum gravity. However, it is known that AdS vacua can appear from compactifying the Standard...

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### HET Seminar at IAS | Grant Remmen, Caltech | “Twofold Symmetries and Simplification of the Gravity Action”

Mon, Oct 2, 2017, 2:30 pm

While the canonical formulation of graviton perturbation theory is calculationally complex, the freedoms of nonlinear field redefinition and gauge fixing allow for immense simplification and the uncovering of new structures in perturbative gravity.

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### HET Seminar | Raghu Mahajan, Princeton U. | "Transport in Chern-Simons-Matter Theories" | PCTS Seminar Rm

Fri, Sep 29, 2017, 1:45 pm

The frequency-dependent longitudinal and Hall conductivities --- $\sigma_{xx}$ and $\sigma_{xy}$ --- are dimensionless functions of $\omega/T$ in 2+1 dimensional CFTs at nonzero temperature. These functions characterize the spectrum of charged excitations of the theory and are basic experimental observables.

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### HET Seminar | Subham Dutta Chowdhury, Indian Institute of Science | "Conformal field theories and three point functions" | PCTS Seminar Rm

Mon, Sep 25, 2017, 2:30 pm

Conformal invariance allows additional unique parity-odd tensor-structures for three-point functions involving the stress tensor, T, and a conserved U(1) current, j, in 2+1 dimensional conformal field theories that violate parity, apart from the usual parity even structures.

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### HET Seminar at IAS | Shota Komatsu, Member, School of Natural Sciences, IAS | “Correlation Functions in N=4 SYM From Integrability”

Fri, Sep 22, 2017, 1:45 pm

I will give an overview of the integrability-based approach to study correlation functions in planar N=4 SYM. The basic strategy is to "divide and conquer": We decompose the correlators of single-trace operators into fundamental objects called hexagon form factors, and compute each hexagon form factor by using integrability.

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### HET Seminar at IAS | Thomas Faulkner, UIllinois at Urbana-Champaign |“The Quantum Null Energy Condition from Causality”

Mon, Sep 18, 2017, 2:30 pm

I will present a general argument for the local bound on the null-null component of the stress tensor in a QFT called the Quantum Null Energy Condition. The argument involves the study of correlation functions of operators undergoing modular evolution associated to sub-regions of the QFT.

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### HET Seminar | Zachary Fisher, Perimeter Institute | "Weak Gravity Conjecture and Black Hole Thermodynamics" | PCTS Sem Rm

Fri, Sep 15, 2017, 1:45 pm

The weak gravity conjecture (WGC) is a proposed bound on the mass of a charged particle in a consistent low-energy effective theory. We study quantum corrections to black hole entropy arising from a charged but WGC-violating scalar.

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### HET Seminar at IAS | Prahar Mitra, Member, School of Natural Sciences, IAS | "Asymptotic Symmetries in Effective Field Theories"

Fri, Sep 8, 2017, 1:45 pm

A complete and universal equivalence between soft theorems inquantum field theories and asymptotic symmetries in flat spacetimes has recently emerged. We review these developments and show that the equivalence also extends to theories with higher derivative interactions.

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