Projects

I am a quantum field theorist with a broad range of interest. I have spent time researching strong interactions, large N gauge theories, the QCD phase diagram, effective field theory and formal aspects of lattice field theory. A major focus of my current research lies at the intersection of particle, nuclear and condensed matter physics. The effort in this area is directed towards exploring the interrelations between topological phases of lattice quantum field theory and that of quantum materials. This direction of research has ties with another research interest of mine relating to quark-Hadron/Higgs-confinement continuity. I also work on nuclear astrophysics where I am trying to build an understanding of the nuclear equation of state that can be helpful towards interpreting neutron-star mass radius observations and gravitational wave signals. And finally, I have worked on axion like dark matter particles and their interactions with plasma. Details of the projects are stated below. 

  • I am interested in the physics of axion dark matter particles and their decay in a medium. I wrote a paper on the decay axion condensates and how the decay gets affected by a surrounding a plasma. I found that the decay of very long wavelength axions is suppressed by the interstellar plasma. Currently I am working on axion decay in time dependent magnetic fields relevant for neutron stars.

  • I am interested in the phase diagram of cold dense QCD and its application to neutron stars. The core of a neutron star can host a soup of nucleons (known as nuclear matter) or quarks (known as quark matter). The properties of the matter inside the core affects the equation of state of neutron star which in turn decides the mass and radius of the star as well as dictates the gravitational waves that emerges from merging neutron stars. Our current understanding of nuclear equation of state is incomplete and new ideas are needed in order to explain all the observed data. Interestingly, a model of nuclear matter, known as quarkyonic matter can help explain some of the essential features of the mass-radius curves of neutron stars.

  • Higgs-confinement complementarity : Higgs and confining regions of a gauge theory are generally believed to be smoothly connected without a phase transition. Although such continuity was demonstrated to exist only for a certain class of gauge theories, the theorem has been applied more generally without much care. My work with collaborators in the context of quark-hadron transition suggests that Higgs and confining regimes of a gauge theory may well be separated by a phase transition under certain circumstances.

  • There are deep ties between lattice field theory and the physics of topological phases of materials. For example, the physics of quantum Hall effect and the corresponding chiral edge states have parallels in anomaly inflow of domain wall fermions on the lattice. Another striking example of this interrelation lies in the commonality between Chern insulators and abelian lattice gauge theories coupled to Wilson fermions. One of the research directions I am pursuing involves exploring the interrelations between lattice gauge theory and topological phases of terrestrial materials with the goal of facilitating a deeper understanding of lattice field theory and leading to designs of new quantum materials. 

  • Quark-Hadron phase transition in dense QCD : Some of the early analysis of emergent phenomena in dense QCD closely followed the developments in condensed matter physics including superfluidity and superconductivity. However, more contemporary techniques involving topological considerations beyond the Ginzburg-Landau paradigm have not been put to use in its study. A direction of my research is focused on revisiting the QCD phase diagram in search of possible new phase transitions beyond the Ginzburg-Landau paradigm involving spontaneous breaking of global symmetries by local order parameters. In fact in a recent paper I and my collaborators uncovered evidence of a new phase transition between quark matter and nuclear matter detectable only using non-local operators like the color Aharonov-Bohm phase around superfluid vortices.