Events

Theory Seminar (High Energy/Cosmology)

<< Fall 2022 Spring 2023 Summer 2023 >>
Subscribe your calendar or receive email announcements of events

Events During the Week of April 9th through April 16th, 2023

Monday, April 10th, 2023

No events scheduled

Tuesday, April 11th, 2023

No events scheduled

Wednesday, April 12th, 2023

Late-time accelerating cosmologies
Time: 1:00 pm - 2:30 pm
Place: Chamberlin 5280
Speaker: Flavio Tonioni, UW Madison
Abstract: In this talk, I will characterize the late-time expansion rate of the universe in scalar-field cosmologies with multi-exponential potentials. To do this, I will take advantage of previously unobserved universal asymptotic features of the solutions to the cosmological equations. This is a critical achievement because it provides a simple diagnostic of whether any given multi-exponential potential holds the necessary conditions for late-time cosmic acceleration. Such potentials have been studied extensively as phenomenological models of quintessence and, moreover, they are ubiquitous in string-theoretic constructions, which further allows one to sharpen several statements on the low-energy signatures of quantum gravity. I will extensively comment on the tension for acceleration posed by the string-theoretic dilaton, which, if present as a rolling scalar in a weakly-coupled theory, makes the potential too steep for acceleration unless negative-definite potentials are present. I will also show that, if the late-time scale factor is of power-law form, the acceleration parameter can be expressed in terms of a directional derivative of the potential.
Host: George Wojcik
Add this event to your calendar

Thursday, April 13th, 2023

No events scheduled

Friday, April 14th, 2023

No events scheduled