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...

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...

We investigate the cubic interactions of a massless higher-spin fermion with gravity in flat space and present covariant 2-s-s vertices, compatible with the gauge symmetries of the system, preserving parity. This explicit construction relies on the...

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...

General arguments indicate that Feynman integrals can be thought as period integrals. In this talk we will focus on the case of the two-loop sunset graph with internal masses. We will show that this integral is given by a period of a variation of a...

Monopole operators play an important role in the dynamics of three-dimensional conformal field theories. In this talk, I will explain how to use the 1/N_f expansion to study these operators at the infrared fixed points of non-Abelian gauge theories...

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...