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High Energy Phenomenology Seminar: Yiming Zhong (UChicago) "Precision Calculation of Inflation Correlators at One Loop"

Speaker: Yiming Zhong (UChicago)
Date: 4/29/2022
Time: 1 p.m.
Location: Room 464
Event Contact: Brandy Koebbe
BKOEBBE@ILLINOIS.EDU
Sponsor: Department of Physics
Event Type: Seminar/Symposium
 
We initiate a systematic study of precision calculation of the inflation correlators at the 1-loop level, starting with bosonic 1-loop bispectrum with chemical-potential enhancement. Such 1-loop processes could lead to important cosmological collider observables but are notoriously difficult to compute due to the lack of symmetries. We attack the problem from a direct numerical approach based on the real-time Schwinger-Keldysh formalism and show full numerical results for arbitrary kinematics containing both the oscillatory "signals" and the "backgrounds". Our results show that, while the non-oscillatory part can be one to two orders of magnitude larger, the oscillatory signal can be separated out by applying appropriate high-pass filters. We have also compared the result with analytic estimates typically adopted in the literature and found there is a non-negligible deviation in the frequency of the oscillatory part away from the extreme squeezed limit. See arXiv:2109.14635 for more details.