Abstract.
The well-established theory of Big Bang Nucleosynthesis (BBN) suggests that the universe must have been thermalized. However, cosmic inflation leaves the universe dominated by vacuum energy at the end of inflation. The subsequent reheating phase, which bridges inflation to the radiation-dominated era preceding BBN, plays a crucial role in shaping the universe's thermal history. This transition influences key processes such as dark matter (DM) production, phase transitions, and baryogenesis in the early universe. Despite its critical importance, probing the reheating era remains a major challenge.
In this talk, I will discuss stochastic gravitational waves (GWs) generated during reheating through graviton emission. I will demonstrate how the GW spectrum can serve as a powerful tool to probe the unknown physics preceding BBN.
(The slides will be available here)