Primordial black holes and gravitational waves from aligned axion inflation

@misc{ijaz2026primordial,
  title = {{Primordial black holes and gravitational waves from aligned axion inflation}},
  author = {Nadir Ijaz},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.41823},
  eprint = {2610.41823},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.41823},
}

TY  - UNPB
TI  - Primordial black holes and gravitational waves from aligned axion inflation
AU  - Nadir Ijaz
PY  - 2026
DA  - 2026/10/30
PB  - arXiv
DO  - 10.48550/arxiv.2610.41823
UR  - https://arxiv.org/abs/2610.41823
AB  - We study the production of primordial black holes (PBHs) and scalar-induced gravitational waves (SIGWs) in aligned axion inflation through the transition between two stages of inflation. The first stage proceeds along a metastable trajectory and ends when this trajectory loses stability, causing the fields to turn towards the attractor of the second inflationary stage. During the transition, coupled adiabatic--entropy evolution produces a localized enhancement of the curvature power spectrum. We compute the PBH abundance from this spectrum assuming Gaussian primordial curvature perturbations and using the nonlinear compaction-function formalism with a spectrum-dependent collapse threshold and critical collapse. Representative benchmark solutions yield asteroid-mass PBHs with a potentially significant dark-matter abundance, together with an associated SIGW background.
ER  -