Reheating is a theory explaining the transition of the Universe from the end of inflation to the radiation phase before Big Bang nucleosynthesis (BBN). Probing the physics before BBN is challenging because the background is not transparent to usual messengers like photons or neutrinos. However, gravitational wave (GW) serves as a very promising portal. In this talk, I will discuss a simple and inevitable stochastic GW spectrum resulting from graviton bremsstrahlung during reheating.  I will demonstrate the dependence of GWs on the shape of the inflaton potential as well as the type of inflaton-matter coupling. Finally, I will highlight the potential of future high-frequency GW detection in probing the dynamics of reheating, which could potentially shed light on the unknown physics before BBN.

Biography

XU,Yong obtained his PhD degree from Bonn University in October 2022. Since December 2022, he has been a postdoctoral researcher at Mainz Institute for Theoretical Physics (MITP), JGU Mainz. His research interests include cosmic inflation, post-inflationary reheating, dark matter production mechanisms, and primordial gravitational waves. 

Inviter

Shi Pi