NISHANT AGARWAL
___________________________________________________
I am a McWilliams Postdoctoral Fellow at the Bruce and Astrid McWilliams Center for Cosmology at Carnegie Mellon University. Before this I was a graduate student in the Department of Astronomy and Space Sciences at Cornell University, working with Prof. Rachel Bean.
Research Interests
My research focuses on studying and developing cosmological models for the evolution of our Universe. It can broadly be classified into the following three areas:
Inflation
The standard model of cosmology postulates that the Universe underwent a rapid expansion in its early phases just after the big bang. Although inflation has become a part of the modern cosmological paradigm, it lacks a firm physical foundation. Various models of inflation have been proposed in the literature - my research has dealt with general, single scalar field inflationary models and brane inflation. Ref: [2], [6]
Dark Energy
Dark energy is the name given to the mysterious force/energy that drives the current acceleration of the Universe. For the simple reason that gravity is attractive, we would have expected the expansion of the Universe to slow down instead. The strange cosmic acceleration can be attributed to some unknown form of matter/energy that exerts negative pressure, or to an infrared modification to Einstein's gravity itself. My work focuses on studying different kinds of modified gravity models, such as scalar-tensor gravity, braneworld scenarios, and massive gravity. Ref: [3], [4], [8]
Pseudoscalar-photon mixing
Light, weakly interacting pseudoscalar particles, such as the axion, are predicted by many extensions of the standard model of particle physics. Since pseudoscalar particles have not been observed to this day, an active area of research is to use direct and indirect methods to search for their presence. In particular, such particles effectively couple to photons, and in the presence of a background magnetic field can oscillate into photons and vice versa. My work has dealt with studying the effects of pseudoscalar-photon coupling on the polarization of cosmic microwave background (CMB) radiation and optical radiation from distant quasars. Ref: [1], [5], [7]