Effects of Poisson Isocurvature Perturbations on Induced Gravitational Waves
Abstract
A sudden transition from an early matter-dominated era to a radiation-dominated era provides a representative mechanism for enhancing induced gravitational waves (GWs). In the primordial black hole (PBH) evaporation scenario, discrete PBH number-density fluctuations naturally generate Poisson isocurvature perturbations. By evaluating the GWs induced by these perturbations through the sudden evaporation transition, we show how the full hierarchy of intrinsic non-Gaussian statistics of a Poisson isocurvature source enters the induced GW spectra. We find that the tensor power spectrum retains only the two-point correlations of the scalar source, while higher-order correlations first appear in the tensor bispectrum. We also find a nontrivial scale dependence in the relative amplitudes of different bispectrum configurations, which may provide additional information for distinguishing the discrete PBH scenario from other induced-GW mechanisms.
Related
- Scalar Perturbations and Induced Gravitational Waves from First-Order Phase Transitions in Lattice Simulations
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- Angular power spectrum of induced gravitational waves: breaking model and parameter degeneracies in PTA observations
- PrimordialPy: A Python library for single-field inflation, primordial black holes, and scalar-induced gravitational waves
- Primordial Black Hole Abundances and Scalar Induced Gravitational Waves from Finite-Width Power Spectra in a Stiff Thermal History
BibTeX
@misc{zhou2026effects,
title = {{Effects of Poisson Isocurvature Perturbations on Induced Gravitational Waves}},
author = {Zi-An Zhou and Cheng-Jun Fang and Zong-Kuan Guo},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.00989},
eprint = {2610.00989},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.00989},
}
RIS
TY - UNPB
TI - Effects of Poisson Isocurvature Perturbations on Induced Gravitational Waves
AU - Zi-An Zhou
AU - Cheng-Jun Fang
AU - Zong-Kuan Guo
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.00989
UR - https://arxiv.org/abs/2610.00989
AB - A sudden transition from an early matter-dominated era to a radiation-dominated era provides a representative mechanism for enhancing induced gravitational waves (GWs). In the primordial black hole (PBH) evaporation scenario, discrete PBH number-density fluctuations naturally generate Poisson isocurvature perturbations. By evaluating the GWs induced by these perturbations through the sudden evaporation transition, we show how the full hierarchy of intrinsic non-Gaussian statistics of a Poisson isocurvature source enters the induced GW spectra. We find that the tensor power spectrum retains only the two-point correlations of the scalar source, while higher-order correlations first appear in the tensor bispectrum. We also find a nontrivial scale dependence in the relative amplitudes of different bispectrum configurations, which may provide additional information for distinguishing the discrete PBH scenario from other induced-GW mechanisms.
ER -