Abstract:

   Heavy particles can be produced on shell during inflation and leave distinct signals in the correlations of density fluctuations. In th is talk I will introduce the basics of this cosmological collider program, and explain why it is nontrivial 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.

Introduction of the speaker:

     Zhong-Zhi Xianyu is currently an assistant professor at Department of Physics, Tsinghua University. He obtained his PhD in 2015 from Tsinghua and was a postdoc at Harvard from 2015 to 2020. He works mainly in theoretica I particle physics and cosmology. His recent research interests include inflation, non-Gaussianity, new physics 1n the early universe, gravitational wave astronomy, etc.

Tencent Meeting: ID: 910 751 372