Events Archive

Many-body ground states and collective excitations in a tunable 2D system
Tue, Nov 8, 2022, 12:30 pm1:30 pm

The Landau levels of a two-dimensional electron system support a plethora of fascinating many-body ground states and collective low-energy excitations, thanks to enhanced electron-electron interactions and the characteristics of the LL wave functions. The n=1 LL is particularly fascinating as it hosts even-denominator fractional quantum Hall…

Noises Off!: The Loudest and Most Spectacular Physics Demos
Fri, May 26, 2023, 4:30 pm5:30 pm
Free and open to the public
Cancelled: "Searching for topological superconductors using ultrasound"| Brad Ramshaw|Asst Professor, Cornell University
Tue, May 23, 2023, 12:00 pm1:30 pm

"Superconductors come in many varieties: we typically classify them based on the symmetry of their superconducting gap, such as s, p, or d-wave. This classification, however, does not tell the entire story because the superconducting gap can also have topological structure. One route to topological superconductivity is to…

Faculty, Postdocs, graduate students
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…

PGI Seminar Series Spring 2023|Swapan Chattopadhyay|UC Berkeley and Fermilab|"Probing the Early and Dark Universe with Atomic Beams"
Fri, May 19, 2023, 12:30 pm1:30 pm

MAGIS-100 is a macroscopic ‘Quantum-Sensor’, based on a 100-meter light-pulse atom interferometer, being built at Fermilab by an international collaboration, in search of the “dark” sector of the universe (“dark” matter and energy) and “early-universe” gravitational wave background. The experiment can potentially search for new forces and test …

HEP Seminar|Swapan Chattopadhyay|UC Berkeley and Fermilab|"Optical Maxwell’s Demon"
Thu, May 18, 2023, 4:00 pm5:00 pm

The technique of “Stochastic Cooling” of phase space of a particle beam, using microwave techniques in the GHz frequency range, has been employed historically in particle colliders, leading to ground-breaking discoveries. ‘Cooling’ increases the probability of interactions in colliding beams, thus enhancing the likelihood of observing rare…

Special Seminar: Solvable Lattice Hamiltonians with Fractional Hall Conductivity|Rm A06 @2PM
Wed, May 17, 2023, 2:00 pm3:00 pm

In this talk, I will present a new systematic approach of constructing solvable lattice Hamiltonians for a large class of 2+1D topological orders, which are enriched by background Electromagnetic U(1) symmetry and feature non-trivial fractional Hall conductivity. This approach goes beyond the conventional fixed-point principle by considering…

Faculty, Postdocs, graduate students
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…

The Standard Model heavyweights: an overview of the latest measurements of the ttW and four-tops processes by the ATLAS experiment|Brendon Bullard
Thu, May 11, 2023, 2:00 pm3:00 pm

Abstract: Measurements of rare Standard Model (SM) processes are now possible thanks to the large trove of collision data delivered by the LHC during its second data taking run. Of particular interest are heavy states including top quarks plus an additional heavy boson (ttH, ttW, and ttZ) and the simultaneous production of four top quarks…

Faculty, post docs, grads
Dark Cosmos - Putting all the X in one basket: X-ray constraints on sub-GeV dark matter |Elena Pinetti, Fermilab| Joseph Henry Rm 5/9 @4PM
Tue, May 9, 2023, 4:00 pm5:00 pm

In this talk I will focus on light dark matter particles, with a mass between 1 MeV and a few GeV. These particles can annihilate or decay into electron-positron pairs which can upscatter the low-energy fields in our Galaxy and produce X-ray emission. By using the X-ray data from XMM-Newton, Integral, Suzaku and NuStar, we derive strong…

Physic faculty, post docs, grads
Condensed Matter: Fluid dynamics of Incompressible Quantum Hall fluids| F. Duncan M. Haldane|Prof of Physics, Princeton University|JH Rm 5/9 @12PM
Tue, May 9, 2023, 12:00 pm1:00 pm

While Laughlin identified the fractional quantum Hall state as a consequence of an “incompressible quantum fluid”, well-described by his model  wavefunction  which exhibits “flux attachment”, no fundamental explanation of the energetics driving “flux attachment” has emerged. A new picture reveals that  a…

Physics faculty, post docs, grads
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…

Biophysics Seminar Series - Lillian Fritz-Laylin
Mon, May 8, 2023, 12:30 pm1:30 pm

Eukaryotic cells physically manipulate their environments; swimming through liquids, crawling across surfaces, and actively ingesting objects large and small. Inside these cells lies a seething mass of cytoplasm through which thousands of different objects are pushed and pulled to specific cellular locations. These and other dynamic processes…

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…

Special Seminar:Josephson junction arrays as a platform for topological phases of matter|Omri Lesser (Weizmann Inst)|May 4 @3:30pm Joseph Henry Rm
Thu, May 4, 2023, 3:30 pm5:00 pm

The search for low-dimensional topological superconductivity is fueled by the promise of new and exotic physics, such as chiral superconductivity and non-Abelian anyons. However, the need to break time-reversal symmetry, usually by applying a relatively large external magnetic field, has hindered the realization of these novel phases of matter…

Physics faculty, post docs, grads
Condensed Matter:Instanton Density Operator in Lattice QCD from Higher Category Theory | Jingyuan Chen ,Tsinghua University (Beijing)|A06 5/1 @2PM
Mon, May 1, 2023, 2:30 pm3:30 pm

A long standing problem in lattice QCD is to construct an explicit instanton density operator on the lattice. We introduce such a construction, after suitably refining the lattice Yang-Mills action, so that it captures the continuum Yang-Mills theory better than the traditional lattice Yang-Mills action does. This refinement needed follows…

Physics faculty, post docs, grads
PGI Seminar Series Spring 2023|Stephen Adler|IAS|"Dynamical Gravastars"
Mon, May 1, 2023, 12:30 pm1:30 pm

I give new results for  “gravastars'', which are horizonless compact objects that closely mimic mathematical black holes in their exterior geometry,  but for which g_{00} is always positive.  They result from  solving the  Tolman-Oppenheimer-Volkoff  (TOV) equations for relativistic stellar structure, which require…

Biophysics Seminar Series - Arseny Finkelstein
Mon, May 1, 2023, 12:30 pm1:30 pm

Regulation of information flow in the brain is critical for many forms of behavior.

In the first part of my talk, I will focus on mechanisms that regulate interactions between brain regions and describe how state-dependent frontal cortex dynamics can gate information flow from the sensory cortex during decision-making in mice.

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…