# Events Archive

## 2016

### Pheno & Vino Seminar, Prateek Agrawal, Harvard, "The Cosmological Constant Problem in Scalar Gravity"

Tue, May 17, 2016, 4:00 pm to 5:30 pm

PLEASE NOTE CHANGE IN LOCATION AND TIME -- 5:00 pm IN JADWIN A07.

### High Energy Theory Seminar IAS - Hong Liu, MIT - “Effective Field Theory of Dissipative Fluids”

Mon, May 16, 2016, 2:30 pm to 3:30 pm

We develop an effective field theory for dissipative fluids which governs the dynamics of long-lived gapless modes associated with conserved quantities. The resulting theory gives an action formulation of fluctuating hydrodynamics which incorporates systematically nonlinear interactions of noises.

### Condensed Matter Seminar, Dmitri Khevshchenko, UNC, "Demystifying the Holographic Mystique"

Mon, May 16, 2016, 1:15 pm to 2:30 pm

Thus far, in spite of many interesting developments,
the overall progress towards a systematic study and classification of various 'strange' metallic states of matter has been rather limited. To that end, it was argued that a recent proliferation of the ideas of

### HET Seminar, Marko Simonivic, IAS, "Weinberg Soft Theorems from Weinberg Adiabatic Modes"

Fri, May 13, 2016, 1:45 pm to 3:00 pm

Soft theorems for the scattering of low energy photons and gravitons and cosmological consistency relations on the squeezed-limit correlation functions are both understood to be consequences of invariance under large gauge transformations.

### Atomic Physics Seminar, Vito Giovanni Lucivero, ICFO, "Quantum metrology with high density atomic vapors and squeezed states of light"

Fri, May 13, 2016, 12:00 pm to 1:30 pm

Nowadays there is a considerable progress in optical magnetometry and spin-noise spectroscopy, which use magnetically-sensitive atomic ensembles and optical read-out, approaching fundamental limits.

### Special CM Seminar, Thomas Iadecola, Boston College, "Wire constructions of Abelian topological phases in three or more dimensions"

Thu, May 12, 2016, 1:30 pm to 3:00 pm

Coupled-wire constructions have proven to be useful tools to characterize Abelian and non-Abelian topological states of matter in two spatial dimensions. In many cases, their success has been complemented by the vast arsenal of other theoretical tools available to study such systems. In three dimensions, however, much less is known about...

### HET Seminar, Daniel Harlow, Harvard University, “Discussion about constraints on electromagnetism from quantum gravity”

Wed, May 11, 2016, 1:30 pm to 3:00 pm

I'll review a few recent papers that discuss the subject in the title, focusing on results based on AdS/CFT.

### Pheno & Vino Seminar, Andrea Tesi, U of Chicago, "The \digamma particle"

Tue, May 10, 2016, 5:00 pm to 6:30 pm

PLEASE NOTE CHANGE IN TIME & LOCATION FOR TODAY'S MEETING 5:00 Room: Jadwin A07

### High Energy Theory Seminar - Tarek Anous, MIT - "Black hole collapse in the 1/c expansion"

Mon, May 9, 2016, 2:30 pm to 3:30 pm

We present a method in 2d CFT for calculating correlators in a state corresponding to the spherical collapse of a shell of matter in three dimensional quantum gravity. In field theory terms, we describe the equilibration process, from early times to thermalization, of a CFT following a sudden injection of energy at time t = 0.

### Condensed Matter Seminar, Roderich Moessner, Max Planck, "Dynamics of a Kitaev spin liquid"

Mon, May 9, 2016, 1:15 pm to 2:30 pm

The excitation spectra of topological phases of matter contain rather
`direct' information about their unusual quasiparticles, while the
corresponding bulk ground states tend to be rather
featureless. Motivated by this observation, we have evaluated the
dynamical structure factor of the Kitaev model on the honeycomb

### High Energy Theory Seminar - Adam Brown, Stanford University - "Hot Bubbles of Nothing"

Thu, May 5, 2016, 1:45 pm to 3:00 pm

“Bubbles of nothing” are a dramatic instability of spacetimes with compact extra dimensions. A hole appears in spacetime, inside of which there is neither space nor time: there is literally “nothing”. Witten showed that they may nucleate by quantum tunneling.

### Physics Group Meeting - IAS - Discussion Group led by Edward Witten, IAS - "On Kevin Costello's Approach to Integrable Spin Systems”

Wed, May 4, 2016, 1:30 pm to 2:30 pm

### Pheno & Vino Seminar, Jesse Thaler, MIT, "Probing the Core of QCD with Jet Substructure"

Tue, May 3, 2016, 4:00 pm to 5:30 pm

Jet substructure techniques have emerged as an essential tool for new physics searches at the LHC. In this talk, I highlight the ways that theoretical studies of jet substructure have revealed fascinating new phenomena in QCD.

### High Energy Theory Seminar - Masahito Yamazaki, Kavli Institute - "Determinant Formulas for General CFTs"

Tue, May 3, 2016, 2:00 pm to 3:00 pm

I will discuss determinant formulas for higher-dimensional CFTs, which was known in the 70's but extended to SCFTs only recently. I will discuss the implications of the formula for the discussion of unitarity bounds and for the analytic structures of conformal blocks.

### High Energy Theory Seminar - Ethan Dyer, Stanford University - "small black holes in near extremal gravity"

Mon, May 2, 2016, 2:30 pm to 3:30 pm

The extremal gravity proposal is a conjectured duality between pure gravity in three dimensions and a speculative set of 2d CFTS. I will discuss a computation of the number of black hole micro-states in these theories.

### Condensed Matter Seminar, Chetan Nayak, Microsoft, "Floquet Time Crystals: Spontaneously Broken Discrete Time-Translational Symmetry in Periodically-D

Mon, May 2, 2016, 1:15 pm to 2:30 pm

I will define what it means for time translation symmetry to be spontaneously broken in a quantum system, and show with analytical arguments and numerical simulations that this occurs in a large class of driven systems with discrete time-translation symmetry.

### HET Seminar IAS - John J. Carrasco, IAS - “Efficiency=Geometry? Decoding the DNA of Prediction in Gauge, Gravity and Effective Field Theories”

Fri, Apr 29, 2016, 1:45 pm to 3:00 pm

One can easily be frustrated by the tremendous redundancy in possible physical description. By this I mean the freedom to choose gauge, make field redefinitions, add any amount of auxiliary spectator matter, and the such. Happily we can exploit such freedom to encourage the emergence of a new duality in gauge theories.

### Gravity Group Seminar, David Spergel (Princeton University) "NASA’s WFIRST mission"

Fri, Apr 29, 2016, 12:00 pm to 1:00 pm

### Informal HET Seminar IAS - Arash Arabi Ardehali, University of Michigan - “High-Temperature Asymptotics of the 4d Superconfomal Index”

Fri, Apr 29, 2016, 11:00 am to 12:00 pm

The 4d superconformal index is a partition function (somewhat analogous to the quantum mechanical Witten index, or the 2d SCFT elliptic genus) that counts supersymmetric operators in 4d superconformal field theories. As a partition function it depends on a ``temperature'' parameter which enters the Boltzmann weights of various operators.

### Neutrino Seminar - Diana Parno, U. of Washington, "Unmasking the Neutrino: The Standard Model and Beyond"

Thu, Apr 28, 2016, 2:00 pm to 3:00 pm

When nonzero neutrino mass was definitively established some fifteen years ago, these neutral,