Dark Cosmos - Enhancing the early universe from rotating axion field|Dr Nicolas Fernandez|April 11 @4PM

Apr 11, 2023, 4:00 pm5:30 pm
Physic faculty, post docs, grads



Event Description

In this talk, I present a novel scenario in which the unexplored cosmological evolution of the axion field, specifically a rotation in field space, gives rise to the observed dark matter abundance, baryon asymmetry of the Universe, and gravitational waves signatures. This rotation of the axion field provides a natural origin for an era of kination domination, characterized by the axion field's kinetic term dominating the energy density, which is preceded by an early era of matter domination. This class of solutions is well motivated because such axion rotations naturally arise from complete particle physics models. Remarkably, no entropy is produced at the end of matter domination, allowing these eras of matter and kination domination to potentially occur even after Big Bang Nucleosynthesis. We explore the implications of this cosmological scenario on the spectrum of possible primordial gravitational waves, its impact on structure formation, and its potential role in ameliorating the Hubble tension.