Search Talks

This course is designed to introduce modern machine learning techniques for studying classical and quantum many-body problems encountered in condensed matter, quantum information, and related fields of physics. Lectures will focus on introducing machine learning algorithms and discussing how they can be applied to solve problem in statistical physics. Tutorials and homework assignments will concentrate on developing programming skills to study the problems presented in lecture.

The first direct detection of gravitational waves from merging black holes in 2015 has opened up new avenues to studying gravity in the strong-field regime, inferring the mass and spin distributions of astrophysical black holes and probing the nature of ultra-dense nuclear matter in the interior of neutron stars. Seven years on, we count approximately 100 detections of gravitational waves from compact binary mergers.
 
These observations are goldmines for precise measurements of the source properties and the discovery of new physics at the edge of our current understanding. Pioneering innovations in detector technology will soon let us put black holes under a microscope, allowing us to push Einstein's theory of gravity to the limit. To do so will require exquisitely accurate theoretical models for the emitted gravitational-wave signal if we are to unlock the full discovery potential.

In this talk, I will discuss some of the most spectacular discoveries from the third observing run of Advanced LIGO and Virgo and their implications. I will also highlight some of the pitfalls and challenges in interpreting gravitational-wave detections.

Zoom Link: https://pitp.zoom.us/j/96161151229?pwd=NExyMitMaWpMTVBsL0VRTjZNbFBvZz09

We develop a new method for bosonizing the Fermi surface. In this method, a system with a Fermi surface is described as a coadjoint orbit of the group of canonical transformations. The method naturally parametrizes the Fermi surface by a bosonic field that depends on the spacetime coordinates and the position on the Fermi surface. The Wess-Zumino-Witten term in the effective action, governing the adiabatic phase acquired when the Fermi surface changes its shape, is completely fixed by the Kirillov-Kostant-Souriau symplectic form on the coadjoint orbit. We show that the resulting local effective field theory captures both linear and nonlinear effects in Landau’s Fermi liquid theory. Possible extensions of the theory are described.  Reference: arXiv:2203.05004.

Zoom Link: https://pitp.zoom.us/j/95453440138?pwd=b0Fmbi9HTU9nYTA3Y2F6dWlha294UT09

I will describe 4pt conformal blocks for scalar operators in diverse dimensions by using a single unified formalism, and explain a property of the conformal blocks known as stability. This stability implies that when writing conformal blocks as certain multivariate series, the coefficients of this expansion only depend on Young diagrams. In particular, we can bosonise the conformal computation and simply focus on compact groups. In this framework the blocks are polynomials of the BC root system after we apply complementation. I will then explain the connection with mathematics and show how to formulate a superconformal Cauchy identity which yields the CPW of any free theory diagram in any dimension. For discussion, I will finally mention q-deformations results.

Zoom Link: https://pitp.zoom.us/j/96912692269?pwd=TE8vT01mam9lQjhVV3VSYUtWR2d5Zz09

I review the main mechanisms that convert fundamental CP-violating parameters (theta_QCD and Kobayashi-Maskawa phase) to the observable electric dipole moments (EDMs). Given recent progress, the EDMs connected to electron spin (paramagnetic EDMs) are calculated. The limit on QCD theta angle is 3 * 10^(-8) and  somewhat subdominant to neutron EDM, but can be improved. The Kobayashi-Maskawa phase contributes to paramagnetic EDMs at the level of 10^{-35} e cm in units of equivalent electron EDM, which is much larger than what was previously expected.  

Zoom Link: https://pitp.zoom.us/j/96502704646?pwd=ZThQWGU2dEZPWjdPQnp2ZEpPVXRIdz09