Hello there! I am a theoretical cosmologist with main interests in the very early Universe and questions pertaining to the origins of the cosmos and the conditions during approximately the first second after the Big Bang (energy scalesi≳i1iMeV). I am especially interested in magnetic fields and gravitational waves in cosmological settings.

Currently, I am a visiting researcher at the University of Geneva, where I am working with Prof. Ruth Durrer on the generation of magnetic fields during inflation with a focus on generating helical fields in axion inflationary models, and with Prof. Chiara Caprini on the generation of vorticity and stochastic gravitational waves during cosmological (first-order) phase transitions. I am also working with Prof. Jennifer Schober in Bonn on the macroscopic effects of the chiral anomaly on primordial magnetic fields and vorticity. More details about my current research can be found here, my publications can be found here, and my CV can be found here.

I obtained my PhD in 2023 from Princeton University, for which I worked with Prof. Ilya Dodin to study the collective effects of GWs interacting with gases and plasmas. My thesis can be found here. We developed  a formalism to capture the backreaction effects of the matter (neutral gases as well as plasmas) and electromagnetic waves on GWs and analytically derived the wave equation for the collective modes of the metric and the matter.

Here is my tongue-in-cheek bio written for our PhD program website, that tries to outline my winding journey to theoretical physics.

Deepen grew up in a small town called Gidderbaha in the state of Punjab, India. From there he went to IIT Bombay for his undergraduate degree in mechanical engineering. Three semesters into college, he realized that he hated his major but it was too late to do anything about it by then. He somehow passed his courses and went on to become an Analytics Consultant in a corporate setting. After 3 years, which he loved, he decided to do something more abstract and fundamental (and if possible, less useful). So he quit his job with the confidence that, of course, there must be many who are looking to fill physics positions with people with no physics background. While he was surprised that this turned out to be not the case, he did manage to find a few generous people who gave him a chance, and after a couple of stints here and there in India, he found himself in the graduate program in Princeton. 

Most of his research time is spent staring at his notebooks in disbelief, bearing the fruits of his idiosyncratic decision-making. When he is not pretending to do Physics, he can be found pretending to know how to swim, or sing acapella, or play table tennis. He really misses the Himalayas, and has, so far, not been able to move on from that, although he has lately increased his efforts to explore American mountains. He likes to go on long runs along the serene canal path where the tranquil Carnegie lake reminds him of the lakes in Kashmir. He never says no to an LOTR marathon, however he does find it difficult to resist the urge to recite the dialogues along.

He is happy to answer any questions about his research, the graduate program, life in Princeton or, in fact, any other topic he may not even be qualified to talk about.