Research Topics

We work on various aspects of cosmology, an overview of which can be found below.

Vector Field Inflation

Inflation driven by vector fields, including explicit and spontaneous Lorentz violation.

Tests of General Relativity and Modified Gravity Theories using Gravitational Wave Astronomy

Read about it here.

Quantum Corrections to Cosmological Models

Recent and upcoming experimental data as well as the possibility of rich phenomenology has spiked interest in studying the quantum effects in cosmology at low (inflation-era) energy scales. Possibility of rich phenomenology as well as detection of low-energy signatures for Planck-scale theories (eg. Lorentz violation) are some of the major motivations. We use the covariant effective action approach to study quantum corrections in cosmological models. Our current work involves developing a covariant framework for quantizing antisymmetric fields with spontaneously broken Lorentz symmetry. The current goal is to obtain the 1-loop effective action and investigate renormalizability.

Higher Derivative Theories

Higher derivative theories are a class of modified gravity theories inspired from renormalizability concerns of gravity at UV scale. However, these theories often give rise to instabilities called “Ostrogradski Instability” arising from the higher order terms in the Lagrangian. Our work focuses on removing such instability from higher derivative theories of gravity.

Bouncing Models in Cosmology

Bouncing cosmology is an alternative paradigm of the early universe cosmology. We are working on a non-singular bounce model and our goal is to test it against observations.

Analog Gravity Models

Analog gravity is a research programme in which we investigate the analog models of General Relativity and Cosmology within other physical systems - Bose Eisntein Condensation specifically. Last decade have seen remarkable development in such models within BEC. Expansion of spacetime, Blackholes, Hawking radiation and Penrose theorem are the few examples.

Large Scale Structure Formation

Cosmological Principle is the basic foundation of Cosmology. But data from many observations suggests the there is a very small anisotropy and inhomogeneity on a very large scale. We use perturbation theory to study that departure from isotropy and homogeneity which leads us to the understanding of Large Scale Structure of the Universe.

Non-Local Cosmology

Observation data suggests that the universe is undergoing an accelerated expansion and convention approach to explain this is by introducing a dark energy term in Einstein-Hilbert action. As is well known that the this approach suffers from a fine tuning problem, we are working on an alternative approach which investigate this accelerated expansion using Non-Local Cosmological Models.