Research Projects

Both the LambdaCDM model of cosmology and the Standard Model (SM) of particle physics have been highly successful in helping us understand our Universe. Nonetheless, various observations and experiments suggest limitations in this framework. Multiple new observations have challenged the standard cosmological paradigm. Furthermore, the questions about dark matter and dark energy still remains unanswered. Neutrino oscillation gives us the evidence for physics beyond the SM. This project will pursue two complementary directions: (1) probing physics beyond Standard Model (BSM) using cosmological and astrophysical data, and (2) exploring extensions beyond FLRW geometries, motivated by observations. In the first direction, we aim to probe BSM interactions within the $\Lambda$CDM framework using observational data, exploring parameter spaces beyond the reach of terrestrial experiments. Remarkably, cosmological and astrophysical observations serve as macroscopic manifestations of underlying particle physics interactions. We will study the effects of DM–SM and neutrino self-interactions on small-scale structure formation. The DM-SM scattering injects 'heat' into cold DM, inhibiting their gravitational collapse, and inducing a power suppression in the small scales of the matter power spectrum. This suppression depends on the DM mass and interaction strength. Observations at those length scales can thus constrain the DM-SM interaction. Novel BSM self-interaction among the neutrinos also induces distinct changes---enhancement and suppression---in the matter power spectrum at the 10--20% level. Both high redshift galaxy count from JWST data and the lensing of gravitational wave (GW) merger events will be valuable probes of such physics, as they target similar scales but with different systematics, making the extraction of BSM physics information more robust. The second direction investigates an inflation-like scenario emerging from a modified ''Cosmological Principle'' that allows for a cosmic flow. We will study the dynamical phase space of a system, including a flow parameter and geometric shear, and track their fixed points as indicators of matter and geometric anisotropies. In summary, this project aims to jointly advance our understanding of cosmology and particle physics by using ongoing and near-future observations to probe BSM interactions and explore novel early Universe geometries. This proposal combines theoretical modelling and diverse observations to address some of the key open questions in modern physics and can lead to new discoveries broadening our understanding of the Universe.