Physics

We use the "lens space index", i.e., the partition function on S^3/Z_r x S^1, to study certain properties of four dimensional gauge theories related to the global structure of the gauge group. We show that the lens space index, unlike the ordinary...

This paper addresses a long standing problem - to identify the chiral ring and moduli space on the Coulomb branch of an N = 4 superconformal field theory in 2+1 dimensions. Previous techniques involved a computation of the metric on the moduli space...

We show how a diffeomorphism invariance of the quantum Hall systems, together with topological consideration, put strong constraints on the physics that goes beyond the Chern-Simons action. We show how the Hall conductivity at finite wavenumbers is...

The axion is a well-motivated dark matter candidate, but is challenging to search for. We propose a new way to search for QCD axion and axion-like-particle (ALP) dark matter. Nuclei that are interacting with the background axion dark matter acquire...

Spontaneous Symmetry Breaking is a very universal concept applicable for a wide range of subjects: crystal, superfluid, neutron stars, Higgs boson, magnets, and many others. Yet there is a variety in the spectrum of gapless excitations even when...

In planar N=4 Super-Yang-Mills theory there is a map between gluons scattering amplitudes and null polygonal Wilson loops. This remarkable duality allows one to make an important step forward by Operator-Product-Expanding the scattering amplitudes...