Dark Interactions 2024

Early Dark Energy During Big Bang Nucleosynthesis

16 Oct 2024, 16:10

20m

Simon Fraser University Harbour Centre

Contributed Talks Dark Sectors

Speaker

Afif Omar (TRIUMF/UVic)

Description

An early dark energy (EDE) component during big bang nucleosynthesis (BBN) affects some observables like the deuterium abundance (D/H), helium fraction ($Y_p$), and the effective relativistic degrees of freedom ($N_{\mathrm{e}\mathrm{f}\mathrm{f}}$). Thus, we propose a model of EDE present during the BBN epoch where the EDE remains constant until a critical time, after which it transitions into either coupled radiation, dark radiation, or kination. By comparing this model's outcomes with observed elemental abundances and $N_{\mathrm{e}\mathrm{f}\mathrm{f}}$ from Cosmic Microwave Background (CMB) data, we constrain the EDE parameters and explore their relationship to BBN inputs like the baryon-to-photon ratio, neutron lifetime, and number of neutrino species. We also explore whether an EDE scenario can resolve the recent tension in primordial helium measurements from EMPRESS.

Presentation materials

BBN_DI20204.pdf