Journal Article

Primordial gravitational waves in the nano-Hertz regime and PTA data — towards solving the GW inverse problem

Morgante, Enrico, Puchades-Ibáñez, Cristina, Schenk, Sebastian, Madge, Eric, Ratzinger, Wolfram, Schwaller, Pedro, Ramberg, Nicklas

2023

Overview

A bstract 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.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V,SpringerOpen
• Subject: Astronomical models / Astrophysics / Axions and ALPs / Benchmarks / Classical and Quantum Gravitation / Cosmology / Cosmology of Theories BSM / Domain walls / Early Universe Particle Physics / Elementary Particles / Gravitational waves / High energy physics / Inverse problems / Laboratory tests / Parameter identification / Particle physics / Phase transitions / Phase Transitions in the Early Universe / Physics / Physics and Astronomy / Pulsars / Quantum Field Theories / Quantum Field Theory / Quantum Physics / Regular Article - Theoretical Physics / Relativity Theory / String Theory / Symmetry / Universe