Abstract
In recent years, several pulsar timing array collaborations have reported first hints for a stochastic gravitational wave background at nano-Hertz frequencies. Here we elaborate on the possibility that this signal comes from new physics that leads to the generation of a primordial stochastic gravitational wave background. We propose a set of simple but concrete models that can serve as benchmarks for gravitational waves sourced by cosmological phase transitions, domain wall networks, cosmic strings, axion dynamics, or large scalar fluctuations. These models are then confronted with pulsar timing data and with cosmological constraints. With only a limited number of free parameters per model, we are able to identify viable regions of parameter space and also make predictions for future astrophysical and laboratory tests that can help with model identification and discrimination.
Original language | English |
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Article number | 171 |
Journal | Journal of High Energy Physics |
Volume | 2023 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 2023 |
Funding
Publisher Copyright: © 2023, The Author(s).
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics