Title: Recent progress in cosmological collider physics
Abstract: Heavy particles can be produced on shell during inflation and leave distinct signals in the correlations of density fluctuations. In this talk I will introduce the basics of this cosmological collider program, and explain why it is in general difficult to get visibly large signals. I will then describe some recent works along this direction with fun physics and naturally large signals, including seeing heavy neutrinos, probing CP violations, and a scenario of Cosmological Higgs Collider where the Higgs interactions can be directly seen via modulated reheating.