TY  - EJOUR
AU  - Domcke, Valerie
AU  - Jinno, Ryusuke
AU  - Rubira, Henrique
TI  - Deformation of the gravitational wave spectrum by density perturbations
IS  - arXiv:2002.11083
M1  - PUBDB-2020-00884
M1  - arXiv:2002.11083
M1  - DESY-20-029
PY  - 2020
N1  - * Temporary entry *30 pages, 8 figures
AB  - We study the effect of primordial scalar curvature perturbations on the propagation of gravitational waves over cosmic distances. We point out that such curvature perturbations deform the isotropic spectrum of any stochastic background of gravitational waves of primordial origin through the (integrated) Sachs-Wolfe effect. Computing the changes in the amplitude and frequency of the propagating gravitational wave induced at linear order by scalar curvature perturbations, we show that the resulting deformation of each frequency bin of the gravitational wave spectrum is described by a linearly biased Gaussian with the variance σ<sup>2</sup>  ≅ ∫dlnk ∆<sub><i>R</i></sub><sup>2</sup>, where ∆<sub><i>R</i></sub><sup>2</sup>(k) denotes the amplitude of the primordial curvature perturbations. The linear bias encodes the correlations between the changes induced in the frequency and amplitude of the gravitational waves. Taking into account the latest bounds on ∆<sub><i>R</i></sub><sup>2</sup> from primordial black hole and gravitational wave searches, we demonstrate that the resulting <i>O</i>(σ) deformation can be significant for extremely peaked gravitational wave spectra. We further provide an order of magnitude estimate for broad spectra, for which the net distortion is <i>O</i>(σ<sup>2</sup>).
LB  - PUB:(DE-HGF)25
DO  - DOI:10.3204/PUBDB-2020-00884
UR  - https://bib-pubdb1.desy.de/record/436006
ER  -