D. Farrah, K. Croker, M. Zevin, G. Tarle, V. Faraoni, S. M. Petty, J. Afonso, N. Fernandez, K. A. Nishimura, C. Pearson, L. Wang, D. L. Clements, A. Efstathiou, E. Hatziminaoglou, M. Lacy, C. McPartland, L. K. Pitchford, N. Sakai, J. Weiner
Abstract
Observations have found black holes spanning 10 orders of magnitude in mass across most of cosmic history. The Kerr black hole solution is, however, provisional as its behavior at infinity is incompatible with an expanding universe. Black hole models with realistic behavior at infinity predict that the gravitating mass of a black hole can increase with the expansion of the universe independently of accretion or mergers, in a manner that depends on the black hole's interior solution. We test this prediction by considering the growth of supermassive black holes in elliptical galaxies over 0 < z ≲ 2.5. We find evidence for cosmologically coupled mass growth among these black holes, with zero cosmological coupling excluded at 99.98% confidence. The redshift dependence of the mass growth implies that, at z ≲ 7, black holes contribute an effectively constant cosmological energy density to Friedmann's equations. The continuity equation then requires that black holes contribute cosmologically as vacuum energy. We further show that black hole production from the cosmic star formation history gives the value of ΩΛ measured by Planck while being consistent with constraints from massive compact halo objects. We thus propose that stellar remnant black holes are the astrophysical origin of dark energy, explaining the onset of accelerating expansion at z ∼ 0.7.
Keywords
Astrophysical black holes; Black hole physics; Supermassive black holes; Dark energy; Star formation; Cosmological constant
The Astrophysical Journal Letters
Volume 944, Number 2
2023 February
