Scalar-Assisted Growth of Supermassive Black Holes: Boson-Mass Windows and Observational Constraints
Abstract
We study a phenomenological cosmological model of black-hole growth in which a finite baryonic reservoir and a bosonic scalar cloud feed the black hole simultaneously. The baryonic component accretes through an Eddington-like channel, while the scalar cloud transfers mass through an effective quasibound-state decay rate. Evolving the system directly in redshift within a flat ΛCDM background, we scan over μ, M0, Mc,0, and Mb,0 to assess whether scalar-assisted accretion can accelerate the formation of 109M⊙ supermassive black holes. We find that the scalar contribution is highly selective in parameter space. For the mass scales explored here, scalar transfer is most efficient for μ∼10−19−10−16 eV, producing rapid cloud depletion and significantly earlier black-hole growth, while outside this interval the evolution remains mainly baryonic. More generally, this efficient window reflects a preferred range of the dimensionless coupling α=μMBH and therefore shifts approximately as μ∝ MBH−1. Comparison with observed quasar masses and luminosities instead favors lower boson masses, broadly around μ∼10−21−10−20eV. These results are not necessarily in tension, since the boson mass that maximizes early growth depends on the characteristic black-hole mass and evolutionary stage. This separation between dynamical efficiency and observational compatibility leaves open complementary roles for different bosonic mass scales in supermassive black hole growth and dark-matter phenomenology.
Related
- Observational constraints on scalar-vector-tensor dark energy with phantom-divide crossing
- Nanohertz Gravitational-Wave Constraints on Supermassive Binary Black Holes at Cosmic Dawn
- Constraints on Supermassive Black Hole Binaries from the Lack of Resolvable Sources in the NANOGrav 15-yr Dataset
- Updated observational constraints on ϕCDM dynamical dark energy cosmological models
- Theoretical consistency and observational constraints on entropic cosmology
BibTeX
@misc{mourelle2026scalarassisted,
title = {{Scalar-Assisted Growth of Supermassive Black Holes: Boson-Mass Windows and Observational Constraints}},
author = {Jorge Castelo Mourelle and Darío Núñez Zúñiga and Saeed Fakhry and Nicolas Sanchis-Gual},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.18986},
eprint = {2610.18986},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.18986},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Scalar-Assisted Growth of Supermassive Black Holes: Boson-Mass Windows and Observational Constraints
AU - Jorge Castelo Mourelle
AU - Darío Núñez Zúñiga
AU - Saeed Fakhry
AU - Nicolas Sanchis-Gual
PY - 2026
DA - 2026/10/13
PB - arXiv
DO - 10.48550/arxiv.2610.18986
UR - https://arxiv.org/abs/2610.18986
AB - We study a phenomenological cosmological model of black-hole growth in which a finite baryonic reservoir and a bosonic scalar cloud feed the black hole simultaneously. The baryonic component accretes through an Eddington-like channel, while the scalar cloud transfers mass through an effective quasibound-state decay rate. Evolving the system directly in redshift within a flat ΛCDM background, we scan over μ, M_0, M_c,0, and M_b,0 to assess whether scalar-assisted accretion can accelerate the formation of 10^9M_⊙ supermassive black holes. We find that the scalar contribution is highly selective in parameter space. For the mass scales explored here, scalar transfer is most efficient for μ∼10^−19−10^−16 eV, producing rapid cloud depletion and significantly earlier black-hole growth, while outside this interval the evolution remains mainly baryonic. More generally, this efficient window reflects a preferred range of the dimensionless coupling α=μM_BH and therefore shifts approximately as μ∝ M_BH^−1. Comparison with observed quasar masses and luminosities instead favors lower boson masses, broadly around μ∼10^−21−10^−20eV. These results are not necessarily in tension, since the boson mass that maximizes early growth depends on the characteristic black-hole mass and evolutionary stage. This separation between dynamical efficiency and observational compatibility leaves open complementary roles for different bosonic mass scales in supermassive black hole growth and dark-matter phenomenology.
ER -