James Clark Maxwell, through his classical theory of electromagnetism, demonstrated that electricity and magnetism are different manifestations of a single underlying electromagnetic force. The story continues as the Standard Model (SM) of Particle Physics successfully unifies the electromagnetic force with the weak nuclear force (the force that is responsible for radioactivity) by establishing the fact that both of them are manifestations of the same underlying force at high energy. The obvious characteristic differences between the forces arise at low energy as the gauge symmetry between them is spontaneously broken by the Higgs field.
However, the incompleteness of SM becomes evident in its inability to predict the relative strengths of all the fundamental forces and to correlate the electric charges of electrons and protons. The limitations of SM are not confounded in theoretical arena; the recent discovery of neutrino oscillation - where one flavor of neutrino transmutes into another flavor, and the existence of dark matter in the universe demand physics Beyond Standard Model (BSM).
A Grand Unified Theory (GUT) invokes a higher symmetry, where all the fundamental interactions (i. strong interaction- the force that makes the nucleus of an atom stable, ii. weak interaction and iii. electromagnetism) except gravity are merged together (Candidates of Theory of Everything like String theory even tries to unify gravity with all other forces). In addition to addressing the SM conundrums such as neutrino oscillation, it also manages to find relations between some of the seemingly unrelated 19 fundamental parameters of SM. As GUT models in general treat quarks and leptons on equal footing and successfully relates the charges of electron and proton; these type of GUT models also end up with a prediction of proton decaying. So, even though the GUT energy scale turns out to be well-beyond the reach of any foreseeable experiments, these models can still be tested through indirect observations like proton decay. The current experimental bound in proton lifetime (proton lifetime p≥1.29×1034 yrs.) sets a severe constraint on GUT models.
My research interest primarily focuses on the construction of minimal yet realistic Grand Unified Theory (GUT) models based on gauge group like SO(10) and E6. The study includes the phenomenological and cosmological aspects of such GUT models, such as the issue of nucleon decay, fermion (especially neutrino) masses and mixings, and the existence of a viable dark matter candidate.
- Symmetry breaking structure of such a higher gauge group (like SO(10) or E6);
- various phenomenological aspects like TeV scale particles, generation of neutrino masses; and
- various cosmological aspects like topological defects of the symmetry breaking, possible candidate for DM candidate; are research interests of mine. The aspiration to be able to explain all physics below the Planck scale also demands the inclusion of the topics like baryogenesis, leptogenesis and flavor puzzle.
Deciphering the fundamental nature of dark matter is currently one of the major issues of theoretical high energy physics. Its origin, nature or interaction is a puzzle yet to be solved. My current and future research interest includes construction and study of such dark matter model. I am particularly interested in the dark matter candidates which arises from GUT models and the models where dark matter and SM particles are unified under some higher gauge symmetry.