Primordial Black Hole Abundances and Scalar Induced Gravitational Waves from Finite-Width Power Spectra in a Stiff Thermal History

@misc{mohammadi2026primordial,
  title = {{Primordial Black Hole Abundances and Scalar Induced Gravitational Waves from Finite-Width Power Spectra in a Stiff Thermal History}},
  author = {Abolhassan Mohammadi and Yogesh and Cristian Joana and Hongwei Tan and Ying-li Zhang},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.07043},
  eprint = {2609.07043},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.07043},
}

TY  - UNPB
TI  - Primordial Black Hole Abundances and Scalar Induced Gravitational Waves from Finite-Width Power Spectra in a Stiff Thermal History
AU  - Abolhassan Mohammadi
AU  - Yogesh
AU  - Cristian Joana
AU  - Hongwei Tan
AU  - Ying-li Zhang
PY  - 2026
DA  - 2026/09/22
PB  - arXiv
DO  - 10.48550/arxiv.2609.07043
UR  - https://arxiv.org/abs/2609.07043
AB  - We study the formation of primordial black holes (PBHs) from large primordial perturbations that re-enter the horizon during an epoch with equation of state w≥1/3. We consider a log-normal curvature power spectrum of finite width Δ and determine the collapse amplitude by numerical-relativity simulations of a self-gravitating perfect fluid. Threshold scans are performed for five values of w and five spectral widths, and the resulting numerical thresholds are used in the PBH abundance and scalar-induced gravitational-wave (SIGW) calculations. For comparison, we also evaluate the semi-analytical q-function prescription. It reproduces the numerical trend close to radiation domination and for nearly monochromatic profiles, but it is not a reliable threshold estimator for generic finite-width profiles in stiffer backgrounds. We show how collapse thresholds increase with both Δ and w, changing the curvature amplitude required for PBHs to constitute all of the dark matter and, consequently, the normalization of the accompanying SIGW signal.
ER  -