Sachs-Wolfe effect as a smoking gun for cosmological gravitational wave backgrounds
Abstract
The Sachs-Wolfe (SW) effect, arising from large-scale structures in the universe, modifies the frequencies of gravitational waves (GWs) sourced by a cosmological background. We show that for backgrounds with ΩGW≳ 10−10, this effect imprints anisotropies and spectral distortions that can be detectable with a network of space-based interferometers (such as LISA + Taiji) and, if not taken into account, may bias the estimate of the theoretical model of the GW background. The effect is particularly enhanced in the high-frequency end of the spectrum. The SW-induced anisotropies and spectral distortions present in a GW background sourced at primordial times will correlate with the SW signature present in the CMB. Any detection of a cross-correlation between the GW anisotropies and the CMB at large scales is therefore a smoking gun for confirming the primordial nature of the background.
Related
- Kantowski Sachs Cosmological Model with Radiation and Generalized Chaplygin Gas
- Cosmological horizons in regular bouncing backgrounds
- Bayesian P-spline recovery of stochastic gravitational-wave backgrounds in LISA
- Reconstructing Early Primordial Black Hole Domination from Gravitational-Wave Backgrounds
- Whispers of Supergravity in Gravitational Wave Backgrounds: Determining the Gravitino Mass from Cosmic Thermal History
BibTeX
@misc{mentasti2026sachswolfe,
title = {{Sachs-Wolfe effect as a smoking gun for cosmological gravitational wave backgrounds}},
author = {Giorgio Mentasti and Leon Vidal and Quentin Baghi and Carlo Contaldi},
howpublished = {arXiv},
year = {2026},
month = jun,
doi = {10.48550/arxiv.2606.14379},
eprint = {2606.14379},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.14379},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Sachs-Wolfe effect as a smoking gun for cosmological gravitational wave backgrounds
AU - Giorgio Mentasti
AU - Leon Vidal
AU - Quentin Baghi
AU - Carlo Contaldi
PY - 2026
DA - 2026/06/12
PB - arXiv
DO - 10.48550/arxiv.2606.14379
UR - https://arxiv.org/abs/2606.14379
AB - The Sachs-Wolfe (SW) effect, arising from large-scale structures in the universe, modifies the frequencies of gravitational waves (GWs) sourced by a cosmological background. We show that for backgrounds with Ω_GW≳ 10^−10, this effect imprints anisotropies and spectral distortions that can be detectable with a network of space-based interferometers (such as LISA + Taiji) and, if not taken into account, may bias the estimate of the theoretical model of the GW background. The effect is particularly enhanced in the high-frequency end of the spectrum. The SW-induced anisotropies and spectral distortions present in a GW background sourced at primordial times will correlate with the SW signature present in the CMB. Any detection of a cross-correlation between the GW anisotropies and the CMB at large scales is therefore a smoking gun for confirming the primordial nature of the background.
ER -