Title: Rare Cosmological Particle Production: Signals in the CMB and Dark Matter Structures
Speaker: Prof. Yuhsin Tsai (Notre Dame University)
Time: 11:00-12:00, May 19 (Tue.), 2026
Place: P512, 5F, General Building III, Nat'l Tsing Hua Univ.

Abstract:
Cosmic inflation provides an environment analogous to a particle collider, capable of producing new particles and imprinting observable signals. In this talk, I will describe a scenario in which particles much heavier than the Hubble scale during inflation are produced through couplings to the inflaton. These particles then propagate classically and enhance curvature perturbations, generating localized signals in the CMB and dark matter structures. I will discuss the properties of the resulting CMB "hotspot" signatures and how such particle production may provide a possible explanation for the luminous high-redshift galaxies observed in the COSMOS-Web survey.