Sixteenth Marcel Grossmann Meeting

Linking the lithium problem and the $H_0$ tension: the gravitational constant at BBN

5 Jul 2021, 18:30

30m

Talk in the parallel session Variation of the fundamental constants, tests of the fundamental symmetries and probes of the dark sector Variation of the Fundamental Constants, Tests of the Fundamental Symmetries and Probes of the Dark Sector

Speaker

Sebastián Franchino-Viñas (Universität Heidelberg - Universidad Nacional de La Plata)

Description

The primordial abundance of lithium is still a subject of controversy, given the disagreement between numerical results and observational estimates. We show how this discrepancy can be undestood in the context of variation of fundamental constants at the epoch of Big Bang Nucleosynthesis. The variation of Newton's constant plays a crucial role. In particular, its interpretation in terms of additional relativistic degrees of freedom suggests an alleviation to the $H_0$ tension.

Presentation materials

franchino.pdf