A cosmological pathway to testable leptogenesis

TL;DR

This paper explores how non-standard cosmological models, such as those with accelerated expansion, can enable low-scale leptogenesis and allow testing early Universe conditions through leptogenesis observations.

Contribution

It introduces a novel connection between non-standard cosmologies and low-scale leptogenesis, suggesting new testable pathways for early Universe physics.

Findings

Non-standard cosmologies can lower the scale of leptogenesis.

Accelerated expansion phases influence leptogenesis viability.

Leptogenesis tests can probe early Universe conditions at high temperatures.

Abstract

Leptogenesis could have occurred at temperatures much lower than generally thought, if the cosmological history of the Universe underwent a period of accelerated expansion, as is predicted for example in a class of scalar-tensor theories of gravitation. We discuss how non-standard cosmologies can open new pathways for low scale leptogenesis. Within these scenarios, direct tests of leptogenesis could also provide information on the very early times Universe evolution, corresponding to temperatures larger than the TeV.