Reheating constraints on the inflaton and dark matter: Swampland conjecture

In this paper, we studied the phenomenological consequences of recently proposed swampland conjecture on the inflationary models through constraints on reheating. If dark matter is assumed to be produced during reheating, the conjecture will provide further constraints on the dark matter parameter space through its current relic abundance. As has been pointed out already and also analyzed in our present paper, any successful inflationary scenario is in clear tension with the aforementioned conjecture in its current form. However considering the swampland parameters to be free and constrained by the inflationary observables, we studied in detail its consequence on the reheating and dark matter phenomenology. We point out the connection between swampland conjecture and the scalar spectral index n(s) by PLANCK within current 2 sigma range, and associated constraints imposed on the reheating temperature and the dark matter annihilation cross section.