Talks

I will give a holographic argument in favor of the AdS Penrose inequality, which conjectures a lower bound on the total mass in terms of the area of apparent horizons. This inequality is often viewed as a test of cosmic censorship. Time permitting, I’ll also discuss a generalization to charged black holes and connections with a quasi-local energy and the second law for apparent horizons.  

I will introduce my recent works on the phenomenology of solutions to the strong CP problem, QCD axion and Parity. I will first describe the production of the QCD axion in the early universe and show that the dark matter abundance is naturally reproduced for a wide range of the parameter space. I will then show a tight relation between the Parity solution, dark matter direct detection, the proton decay, and the precise measurements of the standard model parameters.

Quasars are among the most powerful light sources in the universe and, as such, can be seen at cosmological distances. Is some rare occasions (although not that rare), a massive galaxy on their line of sight can act as a gravitational lens and produce multiple images of distant quasars. These can be used both for cosmology and astrophysics by measuring the so-called time delays between the lensed images from photometric monitoring, a quantity directly related to the Hubble-Lemaître parameter H0. The same data, affected by microlensing by stars in the lensing galaxy, can be used to measure the size and energy profile of quasar accretion disks on spatial scales of the order of the light-day, i.e. inaccessible to even the largest interferometers, including the SKA. The results in this talk are on behalf of the COSMOGRAIL and H0LiCOW collaborations. 

In the first part of the talk, I will mention the ongoing numerical efforts using lattice calculations to understand the holographic dualities relating the super Yang-Mills (SYM) theories in various dimensions and their conjectured Type II supergravity theories in the decoupling limit. In the second part, I will discuss the tensor renormalization group study of the SU(2) gauge-Higgs model in two dimensions using the higher-order tensor renormalization group (HOTRG) algorithm and compare the results with the Monte Carlo simulations.