3 papers
astro-ph.CO2020
Whispers from the dark side: Confronting light new physics with NANOGrav data
Wolfram Ratzinger, Pedro Schwaller
The NANOGrav collaboration has recently observed first evidence of a gravitational wave background (GWB) in pulsar timing data. Here we explore the possibility that this GWB is due…
hep-ph2019
Gravitational wave probes of axion-like particles
Camila S. Machado, Wolfram Ratzinger, Pedro Schwaller +1
We have recently shown that axions and axion-like particles (ALPs) may emit an observable stochastic gravitational wave (GW) background when they begin to oscillate in the early un…
hep-ph2018
Audible Axions
Camila S. Machado, Wolfram Ratzinger, Pedro Schwaller +1
Conventional approaches to probing axions and axion-like particles (ALPs) typically rely on a coupling to photons. However, if this coupling is extremely weak, ALPs become invisibl…