4 papers
Enhanced Matter Power Spectrum from Axion Kination after Big Bang Nucleosynthesis
Raymond T. Co, Nicolas Fernandez, Akshay Ghalsasi +2
Despite stringent constraints from Big Bang Nucleosynthesis (BBN) and cosmic microwave background (CMB) observations, it is still possible for well-motivated particle physics model…
Conversations and Deliberations: Non-Standard Cosmological Epochs and Expansion Histories
Brian Batell, Keith R. Dienes, Brooks Thomas +17
This document summarizes the discussions which took place during the PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pen…
Stochastic Gravitational Waves from Early Structure Formation
Nicolas Fernandez, Joshua W. Foster, Benjamin Lillard +1
Early matter-dominated eras (EMDEs) are a natural feature arising in many models of the early universe and can generate a stochastic gravitational wave background (SGWB) during the…
Axion baryogenesis puts a new spin on the Hubble tension
Raymond T. Co, Nicolas Fernandez, Akshay Ghalsasi +2
We show that a rotating axion field that makes a transition from a matter-like equation of state to a kination-like equation of state around the epoch of recombination can signific…