Speaker: Zach Weiner
Title: Searching for coupled scalars across cosmic history
Room: 3024
Host: Lloyd Knox
Abstract: New scalar fields may couple to the Standard Model by modulating its fundamental parameters in space and time. I will discuss a class of models in which a coupled scalar shifts the electron mass or the electromagnetic fine-structure constant before recombination, paying careful attention to the scalar's gravitational effects, the impact of Standard Model matter on its evolution, and its signatures relevant to complementary probes of fundamental constants at other epochs. I will show that a hyperlight, coupled scalar's gravitational effects open up new degeneracies in cosmological parameters and present quantitative constraints on theoretically consistent scenarios using cosmological data. In the process, I will expound the observational status of early-recombination models in relation to cosmological tensions and comment on the implications of these results for cosmological neutrino mass measurements.
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