Induced gravitational waves in a general cosmological background
Guillem Domènech
Abstract
Gravitational waves (GWs) are inevitably produced by second-order terms in cosmological perturbation theory. Most notably, the so-called induced (GWs) are a window to the small scales part of the primordial spectrum of fluctuations and a key counterpart to the primordial black hole (PBH) scenario. However, semi-analytical solutions are only known for matter and radiation domination eras. In this paper, we present new analytic integral formulas for the induced GWs on subhorizon scales in a general cosmological background with a constant equation-of-state. We also discuss applications to a peaked primordial scalar power spectrum and the PBH scenario.
Topics & Concepts
PhysicsGravitational wavePrimordial black holePerturbation (astronomy)AstrophysicsCosmological constantSpectral densityCosmological perturbation theoryScalar (mathematics)GravitationCosmologyBackground radiationCosmic microwave backgroundDark matterGravitational wave backgroundMatter power spectrumPrimordial fluctuationsScalar fieldQuantum electrodynamicsBaryon acoustic oscillationsFluctuation spectrumGravitational redshiftLambda-CDM modelTheoretical physicsPerturbation theory (quantum mechanics)Cosmic background radiationClassical mechanicsGeneral relativityObservational cosmologyUniverseAstronomyCosmological modelRadiationCosmology and Gravitation TheoriesBlack Holes and Theoretical PhysicsPulsars and Gravitational Waves Research