The rise of the primordial tensor spectrum from an early scalar-tensor epoch
arXiv:2204.10218 · doi:10.1088/1475-7516/2022/08/010
Abstract
Primordial gravitational waves (PGW) produced during inflation span a large range of frequencies, carrying information on the dynamics of the primordial universe. During an early scalar-tensor dominated epoch, the amplitude of the PGW spectrum can be enhanced over a wide range of frequencies. To study this phenomenon, we focus on a class of scalar-tensor theories, well motivated by high energy theories of dark energy and dark matter, where the scalar is conformally and disformally coupled to matter during the early cosmological evolution. For a conformally dominated epoch, the PGW spectrum has a flat step-like shape. More interestingly, a disformally dominated epoch is characterised by a peaked spectrum with a broken power-law profile, with slopes depending on the scalar-tensor theory considered. We introduce a graphical tool, called broken power-law sensitivity curve, as a convenient visual indicator for understanding whether a given broken power-law profile can be detected by GW experiments. We then analyse the GW spectra for a variety of representative conformal and disformal models, discussing their detectability prospects with the Einstein Telescope (ET), Laser Interferometer Space Antenna (LISA), DECi-hertz Interferometer Gravitational wave Observatory (DECIGO), and Big Bang Observer (BBO).
40 pages, 20 figures
References in corpus (18)
- The Confrontation between General Relativity and Experiment
- Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
- BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
- The Swampland: Introduction and Review
- Gravitational-wave sensitivity curves
- Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves
- Challenges and Opportunities of Gravitational Wave Searches at MHz to GHz Frequencies
- Lectures on the Swampland Program in String Compactifications
- Improved Calculation of the Primordial Gravitational Wave Spectrum in the Standard Model
- Improved reconstruction of a stochastic gravitational wave background with LISA
- Disformal Theories of Gravity: From the Solar System to Cosmology
- Gravitational Wave and CMB Probes of Axion Kination
- Primordial Gravitational Wave Signals in Modified Cosmologies
- Mapping the Gravitational-wave Sky with LISA: A Bayesian Spherical Harmonic Approach
- Dilaton and off-shell (non-critical string) effects in Boltzmann equation for species abundances
- Dark matter relic density in Gauss-Bonnet braneworld cosmology
- Asymmetric dark matter in braneworld cosmology
- D-brane Disformal Coupling and Thermal Dark Matter
Cited by in corpus (6)
- Testing BSM Physics with Gravitational Waves
- Role of spatial curvature in the primordial gravitational wave power spectrum
- On the response of the Einstein Telescope to Doppler anisotropies
- Cosmic superstrings in large volume compactifications: PTAs, LISA and time-varying tension
- Chiral gravitational waves from multi-phase magnetogenesis
- Gravitational wave production after inflation for a hybrid inflationary model