Cosmological Impacts of Black Hole Mergers: No Relief in Sight for the Hubble Tension

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Hoelscher, Zachary J., Kephart, Thomas W., Holley-Bockelmann, Kelly
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908629011005440
author Hoelscher, Zachary J.
Kephart, Thomas W.
Holley-Bockelmann, Kelly
author_facet Hoelscher, Zachary J.
Kephart, Thomas W.
Holley-Bockelmann, Kelly
contents The values of the Hubble constant inferred from local measurements and the cosmic microwave background (CMB) exhibit an approximately 5 sigma tension. Some have suggested this tension is alleviated if matter is converted to dark radiation via dark matter decay. As it is not clear that dark matter decays, we instead examine the effects of converting matter to gravitational radiation via black hole mergers. We consider mergers of supermassive black holes (SMBHs), mergers of stellar-mass black holes, and the formation of SMBHs from mergers of smaller black holes. We find that these processes cannot alleviate the tension, as an unrealistically large merger rate, or an overproduction of SMBHs is required. We also consider whether one can use the Integrated Sachs-Wolfe effect to constrain mechanisms that form SMBHs from mergers of smaller black holes. We find that this is also too small to be viable.
format Preprint
id arxiv_https___arxiv_org_abs_2507_23157
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cosmological Impacts of Black Hole Mergers: No Relief in Sight for the Hubble Tension
Hoelscher, Zachary J.
Kephart, Thomas W.
Holley-Bockelmann, Kelly
Cosmology and Nongalactic Astrophysics
The values of the Hubble constant inferred from local measurements and the cosmic microwave background (CMB) exhibit an approximately 5 sigma tension. Some have suggested this tension is alleviated if matter is converted to dark radiation via dark matter decay. As it is not clear that dark matter decays, we instead examine the effects of converting matter to gravitational radiation via black hole mergers. We consider mergers of supermassive black holes (SMBHs), mergers of stellar-mass black holes, and the formation of SMBHs from mergers of smaller black holes. We find that these processes cannot alleviate the tension, as an unrealistically large merger rate, or an overproduction of SMBHs is required. We also consider whether one can use the Integrated Sachs-Wolfe effect to constrain mechanisms that form SMBHs from mergers of smaller black holes. We find that this is also too small to be viable.
title Cosmological Impacts of Black Hole Mergers: No Relief in Sight for the Hubble Tension
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2507.23157