Gravitational waves from global cosmic strings and cosmic archaeology

• Published in: The journal of high energy physics Vol. 2022; no. 3; pp. 114 - 47
• Main Authors: Chang, Chia-Feng, Cui, Yanou
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2022; Springer Nature B.V; Springer Nature; SpringerOpen
• Subjects: Archaeology; Astronomical models; Beyond Standard Model; Big bang cosmology; Classical and Quantum Gravitation; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Cosmology; Cosmology of Theories beyond the SM; Dark matter; Elementary Particles; Emission analysis; Frequency spectrum; Global Symmetries; Gravitational waves; High energy physics; Nuclear fusion; Nuclei (nuclear physics); Particle physics; Physics; Physics and Astronomy; Pulsars; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Standard model (particle physics); String Theory; Strings; Topological Field Theories; Global Symmetries; Topological Field Theories; Cosmology of Theories beyond the SM; Beyond Standard Model
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2022)114

A bstract Global cosmic strings are predicted in many motivated extensions to the Standard Model of particle physics, with close connections to axion dark matter physics. Recent studies suggest that, although subdominant relative to Goldstone emission, gravitational wave (GW) signals from global strings can be detectable with current and planned GW detectors such as LIGO, LISA, DECIGO/BBO, ET/CE and AEDGE/AION, as well as pulsar timing arrays such as PPTA, NANOGrav and SKA. This work is an extensive, updated study on GWs from a global cosmic string network, taking into account of the most recent developments related to the subject. The main analysis is based on the analytical Velocity-dependent One-Scale (VOS) model calibrated with recent simulation results, which provides a generic protocol for such calculations with details given. We also demonstrate how the GW signal can be influenced with variations to the baseline model: this includes considering the uncertainties of model parameters and the potential deviation from the conventional VOS model prediction (i.e. the scaling behavior) as suggested by some of the recent simulation results. Furthermore, we investigated in detail the effect of a non-standard cosmology (e.g. early matter domination or kination) or new particle species on the GW signals from global strings. We demonstrate that the frequency spectrum of GW background from global cosmic strings can be used to probe the cosmic history prior to the Big Bang nucleosynthesis (BBN) (i.e. the primordial dark age) up to a temperature of T ∼ 10 8 GeV.