Primordial black holes from a type-IIB/F theory inflaton potential
Abstract
We study the possibility of the formation of primordial black holes (PBHs) using an inflaton potential constructed by stabilizing all Kähler moduli employing both the perturbative and non-perturbative corrections in the large volume scenario in type-IIB/F string theory. We further introduce a small perturbation in one of the Kähler moduli that modifies the existing potential in the field space. The effective correction in the moduli space is made by introducing a localised Gaussian bump, which induces an ultra-slow-roll feature in the inflaton potential during the early cosmological inflation. The evolution of the amplitude of the curvature power spectrum is solved numerically by using the Mukhanov-Sasaki equation, with Bunch-Davies initial conditions. The inclusion of the Gaussian bump produces a sustainable enhancement in the amplitude of curvature power spectra around k∼ 1.12 × 109 Mpc−1 for the formation of PBHs. The abundance of PBHs (fPBH) is calculated using the Press-Schechter formalism for different values of critical density contrast and presented in the background of contemporary fPBH bounds and checked for viability with existing microlensing bounds, corresponding to a mass value 10−6M⊙ for δ threshold value δc=0.439. The Hawking temperature and evaporation time are also determined for these black holes and found to be of the order of 2.78× 10−15 GeV and 8.5×1038 Gyr, respectively. The enhancement of curvature power spectra lies in the sensitivity region of the SKA observations, suggesting an indication that scalar-induced gravity waves may be probed in future observations.
Related
- Inflaton accretion onto primordial black holes during reheating
- Theory-constrained hierarchical inference of primordial black holes in f(Q, T) gravity with GWTC-3
- Search for subsolar primordial black holes in low mass-ratio binaries with LIGO-Virgo O2 data and implications for the primordial black hole dark matter fraction
- Gravitational wave signals from primordial black holes orbiting solar-type stars
- All Dark Matter as Primordial Black Holes: a Gravitational-Wave Test
BibTeX
@misc{sarkar2026primordial,
title = {{Primordial black holes from a type-IIB/F theory inflaton potential}},
author = {Chitrak Sarkar and Amitava Choudhuri and Buddhadeb Ghosh},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.36863},
eprint = {2610.36863},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.36863},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Primordial black holes from a type-IIB/F theory inflaton potential
AU - Chitrak Sarkar
AU - Amitava Choudhuri
AU - Buddhadeb Ghosh
PY - 2026
DA - 2026/10/27
PB - arXiv
DO - 10.48550/arxiv.2610.36863
UR - https://arxiv.org/abs/2610.36863
AB - We study the possibility of the formation of primordial black holes (PBHs) using an inflaton potential constructed by stabilizing all Kähler moduli employing both the perturbative and non-perturbative corrections in the large volume scenario in type-IIB/F string theory. We further introduce a small perturbation in one of the Kähler moduli that modifies the existing potential in the field space. The effective correction in the moduli space is made by introducing a localised Gaussian bump, which induces an ultra-slow-roll feature in the inflaton potential during the early cosmological inflation. The evolution of the amplitude of the curvature power spectrum is solved numerically by using the Mukhanov-Sasaki equation, with Bunch-Davies initial conditions. The inclusion of the Gaussian bump produces a sustainable enhancement in the amplitude of curvature power spectra around k∼ 1.12 × 10^9 Mpc^−1 for the formation of PBHs. The abundance of PBHs (f_PBH) is calculated using the Press-Schechter formalism for different values of critical density contrast and presented in the background of contemporary f_PBH bounds and checked for viability with existing microlensing bounds, corresponding to a mass value 10^−6M_⊙ for δ threshold value δ_c=0.439. The Hawking temperature and evaporation time are also determined for these black holes and found to be of the order of 2.78× 10^−15 GeV and 8.5×10^38 Gyr, respectively. The enhancement of curvature power spectra lies in the sensitivity region of the SKA observations, suggesting an indication that scalar-induced gravity waves may be probed in future observations.
ER -