IAS Program on Particle Theory:- Analytic Formulae for Inflationary Correlators with Dynamical Mass
Massive fields can imprint distinct oscillatory features, known as the cosmological collider signal, onto primordial correlation functions or inflationary correlators. In this work, the speaker and his team delve into an analytical exploration of the effects of a time-dependent mass of a scalar field on inflationary correlators, which uncover novel phenomenological implications that have remained obscured in previous studies. The time-dependent mass for the heavy particle is naturally induced by couplings to the slow-roll inflaton background, leading to sizable effects, particularly when the couplings do not respect the shift symmetry of the inflaton. Their calculation incorporates techniques developed in the cosmological bootstrap program. Furthermore, by employing a linear order approximation for the time dependence, they obtain an analytical expression for mode functions of the massive scalar. Based on these foundations, they derive analytical formulae for two-, three-, and four-point correlators with the tree-level exchange of the massive scalar. The formulae enable a comprehensive analysis of the phenomenological impact. Notably, their findings reveal modifications in the scaling behavior of the bispectrum in the squeezed configuration, i.e., the cosmological collider signal, characterized by a scale-dependent Boltzmann suppression. They also emphasize that couplings between the inflation and the massive particle can be determined in principle by observing the scaling behavior in detail.
時間：2023.11.07(二) 16:00~17:00
地點：香港科技大學 李兆基校園 盧家驄薈萃樓 高研院4042室
講者：Fumiya SANO (韓國 基礎科學研究院)
語言：英語
免費講座。座位先到先得
【此屬轉載信息，以主事單位發布為準】
*기초과학연구원 Institute for Basic Science
此活動由香港科技大學 賽馬會高等研究院主辦。
https://ias.hkust.edu.hk/events/analytic-formulae-for-inflationary-correlators-with-dynamical-mass
