Title: Model building aspects of cosmological collider

Speaker: Shuntaro Aoki (RIKEN iTHEMS)

Time: 2:00 pm, Sept 25 (Thursday) 2025

Venue: Room W260,Physics Building

Abstract: The cosmological collider program, which aims to extract direct information about heavy particles during inflation via primordial non-Gaussianity, has attracted attention as it offers a window into high-energy physics beyond the reach of terrestrial experiments. However, analyses based on concrete particle physics models remain limited, and it is still unclear under what conditions a large cosmological collider signal can be generated. In this talk, we investigate the criteria for achieving a large signal in a generic framework, focusing on tree-level massive scalar exchange. We further confirm our findings explicitly using several multifield R2 and alpha-attractor inflation models.

Bio: Aoki is a researcher at RIKEN iTHEMS specializing in particle physics and cosmology. His work focuses on the "cosmological collider" program, using primordial non-Gaussianity to probe new physics beyond the Standard Model. He obtained his PhD from Waseda University in 2018.