Constraints on the cosmological coupling of black holes from Gaia

Abstract

Recent work has suggested that black holes (BHs) could be cosmologically coupled to the accelerated expansion of the universe, potentially becoming a candidate for dark energy. This would imply BH mass growth following the cosmological expansion, with the masses of individual BHs growing as $M_{\mathrm{BH}}\propto (1+z{)}^3$. In this letter, we discuss the binary systems Gaia BH1 and Gaia BH2, which contain $\sim 9M_{\odot }$ BHs orbited by $\sim 1M_{\odot }$ stars in widely-separated orbits. The ages of both systems can be constrained by the properties of the luminous stars. If BH masses are indeed growing as $(1+z{)}^3$, the masses of both BHs at formation would have been significantly smaller than today. We find a 77% probability that the mass of the BH in Gaia BH2 would have been below $2.2M_{\odot }$ at formation. This is below the classical Tolman-Oppenheimer-Volkov limit, though it is not yet clear if BHs subject to cosmological coupling should obey this limit. For Gaia BH1, the same probability is 70%. This analysis is consistent with results from two BHs in the globular cluster NGC3201, but unlike the NGC3201 BHs, the Gaia BHs have well-constrained inclinations and thus firm upper mass limits. The discovery of more BHs in binary systems with Gaia astrometry in the coming years will allow us to test the cosmological coupling hypothesis decisively.

submitted 8th March 2023; accepted 2nd May 2023; 4 pages, 3 figures

References in corpus (16)

• Gaia Data Release 3: Summary of the content and survey properties
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• A Luminous Quasar at Redshift 7.642
• Cygnus X-1 contains a 21-solar mass black hole -- implications for massive star winds
• Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry
• A Sun-like star orbiting a black hole
• The Pair-Instability Mass Gap for Black Holes
• Cosmological expansion and local physics
• Constraining the thermally pulsing asymptotic giant branch phase with resolved stellar populations in the Large Magellanic Cloud
• A red giant orbiting a black hole
• Observational evidence for cosmological coupling of black holes and its implications for an astrophysical source of dark energy
• Black hole formation and fallback during the supernova explosion of a $40{\mathrm{M}}_{\odot }$ star
• A Preferential Growth Channel for Supermassive Black Holes in Elliptical Galaxies at z<2
• Implications of Symmetry and Pressure in Friedmann Cosmology. I. Formalism
• Inferring the neutron star maximum mass and lower mass gap in neutron star-black hole systems with spin
• Constraints on the Cosmological Coupling of Black Holes from the Globular Cluster NGC 3201

Cited by in corpus (10)

• Cosmological coupling of nonsingular black holes
• DESI Dark Energy Time Evolution is Recovered by Cosmologically Coupled Black Holes
• Black holes as the source of dark energy: a stringent test with high-redshift JWST AGNs
• Quasi-local masses and cosmological coupling of black holes and mimickers
• Implications of cosmologically coupled black holes for pulsar timing arrays
• Black hole event horizons are cosmologically coupled
• Constraints on cosmologically coupled black holes from gravitational wave observations and minimal formation mass
• Observational implications of cosmologically coupled black holes
• Models of cosmological black holes
• Cosmological coupled black holes immersed in dark sector