Gravitational Waves Induced by Scalar Perturbations with a Broken Power-law Peak

TL;DR

This paper provides an analytical approximation for the energy spectrum of scalar-induced gravitational waves generated by a broken power-law spectrum, highlighting distinct features and aiding rapid data analysis.

Contribution

It introduces a new analytical approximation for SIGW spectra from broken power-law spectra, capturing key features efficiently.

Findings

Analytical approximation accurately models SIGW spectra.

Both asymptotic tails and intermediate peaks influence the spectrum.

The method covers a wide range of models for rapid analysis.

Abstract

We give an analytical approximation for the energy spectrum of the scalar-induced gravitational waves (SIGWs) generated by a broken power-law power spectrum, and find that both the asymptotic power-law tails and the intermediate peak contribute distinct features to the SIGW spectrum. Moreover, the broken power-law power spectrum has abundant near-peak features and our results can be used as a near-peak approximation that covers a wide range of models. Our analytical approximation is useful in the rapid generation of the SIGW energy spectrum, which is beneficial for gravitational wave data analysis.