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…

"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…

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 …

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…

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…

 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…

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…

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…

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…

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…

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…

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…