Executive Summary : | The project aims to find a common origin of dark matter, baryon asymmetry and cosmic inflation. While dark matter and baryon asymmetry are observed phenomena supported by astrophysics and cosmology observations, cosmic inflation a very popular and predictive framework invoked to solve the problems of standard model of cosmology, particularly the horizon and the flatness problems. The same scenario can also simultaneously explain the origin of fluctuations responsible for structure formation in the universe. The standard model of particle physics can not explain the origin of dark matter and baryon asymmetry. The remarkable similarity in the abundance of dark matter and baryon, within same order of magnitude, also motivates to find their common origin. Similarly, a period of accelerated expansion in the very early universe or inflation can not be realized within the standard model requiring additional new physics. Although these problems can be solved independently of each other, it is very economical and predictive to solve them within the same setup. The project aims to find origin of dark matter and baryon asymmetry from the same scalar field introduced to play the role of inflaton. This will be attempted in two broad ways. Firstly, the inflaton field itself will be considered as the dark matter which produces baryon asymmetry either via annihilation or incomplete decay. The same process also reheats the universe leading to a radiation dominated era after inflation. If inflaton couple to the standard model leptons via lepton number violating operators, the observed baryon asymmetry can be produced via leptogenesis as well. In a UV complete framework, such operators can be realized by incorporating additional heavy fields which can also lead to the origin of light neutrino masses. In the second scenario, the relatively less explored scenario known as warm inflation will be studied from the point of view of baryon-dark matter cogenesis. In such a setup, the inflaton field has non-trivial couplings to additional gauge bosons or particles which lead to a dissipative term in the potential without destroying the flatness. This can lead to the production of bath particles throughout the inflationary stage in contrast to the usual slow-roll inflation where particles are produced only during the reheating and preheating eras. Depending upon the symmetry and particle content, the inflaton can produce other heavy baryon and lepton number violating particles which can produce the observed baryon asymmetry from subsequent decay. The project aims to study the possibility of warm inflaton playing a non-trivial role in cogenesis of baryon asymmetry and dark matter. Testability of these scenarios will also be studied at future CMB and dark matter experiments while looking for connections to other observations, anomalies in particle physics. This can lead to complementary probes of the model at cosmic, intensity and energy frontier experiments in near future. |