5 papers
High-frequency Gravitational Waves from Superstring Phases in the Early Universe
Joseph P. Conlon, Edmund J. Copeland, Edward Hardy +1
When moduli roll in the early universe, all physical scales - including string tensions - simultaneously evolve. The dynamics of cosmic string loops with time-varying tension can p…
Supernova bounds on new scalars from resonant and soft emission
Edward Hardy, Anton Sokolov, Henry Stubbs
We study supernova cooling constraints on new light scalars that mix with the Higgs, couple only to nucleons, or couple only to leptons. We show that in all these cases scalars wit…
Dynamical Systems and Superstring Phases in the Early Universe
Noelia Sánchez González, Joseph P. Conlon, Edmund J. Copeland +1
We study the string theory dynamics of the volume scalar rolling down an exponential potential during the period between inflation and reheating, in a background of cosmic superstr…
Searching for heavy millicharged particles from the atmosphere
Han Wu, Edward Hardy, Ningqiang Song
If millicharged particles (MCPs) exist they can be created in the atmosphere when high energy cosmic rays collide with nuclei and could subsequently be detected at neutrino experim…
Searching for a dark matter induced galactic axion gradient
Edward Hardy, Mario Reig, Juri Smirnov
An ultra-light axion with CP violating interactions with a dark sector and CP preserving interactions with the visible sector can act as a novel portal between dark matter and the…