The Tolerable Inhomogeneity of the Baryon Asymmetry

by Stefan Stelzl (IFAE)

Thursday Nov 27, 2025, 12:00 PM → 1:00 PM Europe/Madrid

IFAE Seminar Room (In-Person)

In this talk I present the implications of precision measurements of light element abundances in concordance with the Cosmic Microwave Background for scenarios of physics beyond the Standard Model that generate large inhomogeneities in the baryon-to-photon ratio. We show that precision Big Bang Nucleosynthesis (BBN) imposes strong constraints on any mechanism that produces large scale inhomogeneities at temperatures of the order or below a TeV. In particular, we find that inhomogeneities of the order of at comoving length scales larger than the comoving horizon at the temperature of are in conflict with the measured light element abundances. I then briefly highlight the phenomenological consequences thereof.