Gravitational archeology
Gravitational waves of primordial origin, e.g. cosmic strings or tensor modes from inflation, have propagated during most of the history of the universe. A future detection would tell us information about the energy content in the universe at all those epochs. We study the detectability of an early non-standard era, e.g. matter, inflation, kination and the associated particle physics scenario.
Published in: JCAP 07 (2020) 032 e-Print: 1912.02569 [hep-ph]
We revisit in details the gravitational wave spectrum from local and global cosmic string in arbitrary cosmology. We study in particular the impact of an early non-standard matter era, kination era and inflation era.
We account for particle production.
Published in: JCAP 07 (2020) 016 e-Print: 1912.03245 [hep-ph]
We focus on the presence of an early matter era and deduce the constraints on particle physics model (heavy dark photon, heavy moduli and gravitationally-produced relic)
e-Print: 2111.01150 [hep-ph]
In a long and detailed paper, we study how the potential detection of gravitational waves of primordial origin (cosmic strings, inflation, 1stOPTs) would tell us about the existence of a kination-dominated era. We study in details how such a kination era can arise from a rotating complex scalar field of Affleck-Dine type.
e-Print: 2108.10328 [hep-ph]
We study the enhancement of gravitational wave amplitude from primordial inflation in presence of a kination era induced by a rotation complex scalar field.
PBHs, with masses smaller than 1000 tons (10^9 g), evaporate before the onset of Big-Bang nucleosynthesis, making their detection a challenging task. We propose a strategy to probe the existence of these PBHs through GWs emitted by local and global cosmic strings. Our study provides new insights on the suppression of the GW spectrum and how the spectral shape of local-string GWs can give us information on the duration of the matter era. We have also discovered a novel feature, the double-step suppression, which is universal to any early matter-dominated era, not just specific to PBHs. This research could help set constraints on PBHs with masses between 10^6 and 10^9 g for local strings and between 10^4 and 10^9 g for global strings.
