My research interests lie in the intersection of Cosmology, Gravitation, and High Energy Physics. I employ analytical and numerical methods to connect the various astrophysical and cosmological observations to the theoretical models. My main research interests are as follows:

Primordial Gravitational Waves from Pulsars Timing Array Experiments

Recently, I investigated the implications of the possibility of primordial gravitational waves from the recent discovery of a stochastic gravitational wave background from various pulsar timing array experiments such as NANOGrav, EPTA, PPTA, and IPTA. I used recent measurements from these experiments to constrain the reheating phase of the Universe. By performing the Bayesian analysis, it can be shown that the current measurements prefer instant reheating. I further discuss several ways to reconcile the predictions of PTA experiments to other interferometers such as LIGO/VIRGO bounds of GW energy density and current CMB/BBN bounds on additional. A detailed discussion of this topic can be found here.

Alternative to Inflation: Bounce and Cyclic Universe

I consider the thermodynamical behavior of Banks-Zaks theory close to the conformal point in a cosmological setting. Due to the anomalous dimension, the resulting pressure and energy density deviate from that of radiation and result in various interesting cosmological scenarios. Specifically, for a given range of parameters, one avoids the cosmological singularity. Considering the Banks-Zaks theory with additional perfect fluid yields an even richer phase diagram that includes the standard Big Bang model, stable single ”normal” bounce, dS Bounce, and stable cyclic solutions. The bouncing and cyclic solutions have no singularities, and the violation of the NEC happens only near the bounce. I also provide simple analytical conditions for the existence of these non-singular solutions. Hence, within effective field theory, we have a new alternative non-singular cosmology based on the anomalous dimension of Bank-Zaks theory that may include inflation without resorting to scalar fields.