  Post-inflationary reheating phase is usually said to be solely governed by
the decay of coherently oscillating inflaton into radiation. In this
submission, we explore a new avenue toward reheating through the evaporation of
primordial black holes (PBHs). After the inflation, if PBHs form, depending on
its initial mass, abundance, and inflaton coupling with the radiation, we found
two physically distinct possibilities of reheating the universe. In one
possibility, the thermal bath is solely obtained from the decay of PBHs while
inflaton plays the role of dominant energy component in the entire process. In
the other possibility, we found that PBHs itself dominate the total energy
budget of the Universe during the course of evolution, and then its subsequent
evaporation leads to radiation dominated universe. Furthermore, we analyze the
impact of both monochromatic and extended PBH mass functions and estimate the
detailed parameter ranges for which those distinct reheating histories are
realized.
