Research

We have a well-established theory that explains our universe at the first order. However, at higher orders, more interesting features are revealed. Gravitational waves are theorized to give a clue about the conditions of the early universe. My primary focus is researching and building the theoretical framework to look for gravitational waves generated during the period of inflation, reheating, and hyperkination in higher order phi^2 R^2 modified gravity using the Palatini formalism. The secondary focus is to put constraints on the obtained numerical values using archival and current observational data and present the future scope of detection.

GW170817 marked the start of the era of multi-messenger astronomy. However, so far, no other GW signal, along with its electromagnetic counterpart, has been detected, but the possibility of such events occurring far above our detection capabilities cannot be denied. We present a formalism that seeks to find such events submerged in the GW background using multi-band (gamma-rays, X-ray, UV, optical, IR, Radio, neutrino) time-domain cross-correlation.  The formalism can be readily applied to the loud, sub-threshold, stochastic GW events along with the yet-to-be-detected signals from core-collapse supernovae.

Cosmic ray muons have an unknown origin, and their cascade in the upper atmosphere further complicates the problem. Their exact source has been a mystery. However, the Sun emits some that travel all the way to the Earth. We addressed this using total solar eclipses to study those emissions qualitatively and quantitatively with an emphasis on their temporal variation with the distance between Earth and the Sun using the Fermilab's global muon detector network.