Implications of cosmologically coupled black holes for pulsar timing arrays

Abstract

It has been argued that realistic models of (singularity-free) black holes (BHs) embedded within an expanding Universe are coupled to the large-scale cosmological dynamics, with striking consequences, including pure cosmological growth of BH masses. In this pilot study, we examine the consequences of this growth for the stochastic gravitational wave background (SGWB) produced by inspiraling supermassive cosmologically coupled BHs. We show that the predicted SGWB amplitude is enhanced relative to the standard uncoupled case, while maintaining the ${\Omega }_{\text{gw}}\propto f^{2/3}$ frequency scaling of the spectral energy density. For the case where BH masses grow with scale factor as $M_{\text{bh}}\propto a^3$, thus contributing as a dark energy component to the cosmological dynamics, ${\Omega }_{\text{gw}}$ can be enhanced by more than an order of magnitude. This has important consequences for the SGWB signal detected by pulsar timing arrays, whose measured amplitude is slightly larger than most theoretical predictions for the spectrum from inspiraling binary BHs, a discrepancy which can be alleviated by the cosmological mass growth mechanism.

13 pages, 4 sub-figures arranged into 2 figures. v2: added new references, added new sub-figure, adjusted and explained more clearly some aspects of the analysis and the significance of Fig. 2, slight change in title, fixed a few minor typos. Version accepted for publication in Scientific Reports

References in corpus (48)

• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• Search for an isotropic gravitational-wave background with the Parkes Pulsar Timing Array
• Searching for the nano-Hertz stochastic gravitational wave background with the Chinese Pulsar Timing Array Data Release I
• The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
• The NANOGrav 15-year Data Set: Search for Signals from New Physics
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• The stochastic gravitational-wave background from massive black hole binary systems: implications for observations with Pulsar Timing Arrays
• The NANOGrav 15-year Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational Wave Background
• Gravitational waves from resolvable massive black hole binary systems and observations with Pulsar Timing Arrays
• Mimetic gravity: a review of recent developments and applications to cosmology and astrophysics
• Expected properties of the first gravitational wave signal detected with pulsar timing arrays
• Inflationary interpretation of the stochastic gravitational wave background signal detected by pulsar timing array experiments
• Cosmological expansion and local physics
• McVittie's Legacy: Black Holes in an Expanding Universe
• Primordial gravitational waves from NANOGrav: a broken power-law approach
• Observational evidence for cosmological coupling of black holes and its implications for an astrophysical source of dark energy
• Cosmological Background Interpretation of Pulsar Timing Array Data
• The Effect of Orbital Eccentricity on Gravitational Wave Background Radiation from Supermassive Black Hole Binaries
• Prospects for gravitational-wave detection and supermassive black hole astrophysics with pulsar timing arrays
• Interactions between multiple supermassive black holes in galactic nuclei: a solution to the final parsec problem
• Binary super-massive black hole environments diminish the gravitational-wave signal in the pulsar timing band
• Gravitational Waves from SMBH Binaries in Light of the NANOGrav 15-Year Data
• Spectrum of Primordial Gravitational Waves in Modified Gravities: A Short Overview
• Implications of Pulsar Timing Array Data for Scalar-Induced Gravitational Waves and Primordial Black Holes: Primordial Non-Gaussianity $f_{\mathrm{NL}}$ Considered
• Dynamical evolution of cosmic supermassive binary black holes and their gravitational wave radiation
• Did we hear the sound of the Universe boiling? Analysis using the full fluid velocity profiles and NANOGrav 15-year data
• How the expansion of the universe determines the causal structure of McVittie spacetimes
• Single field inflation in the light of Pulsar Timing Array Data: Quintessential interpretation of blue tilted tensor spectrum through Non-Bunch Davies initial condition
• Scalar induced gravity waves from ultra slow-roll Galileon inflation
• Broken blue-tilted inflationary gravitational waves: a joint analysis of NANOGrav 15-year and BICEP/Keck 2018 data
• Constraints On Scalar-Induced Gravitational Waves Up To Third Order From Joint Analysis of BBN, CMB, And PTA Data
• Implications of Symmetry and Pressure in Friedmann Cosmology. I. Formalism
• The effect of differential accretion on the Gravitational Wave Background and the present day MBH Binary population
• Cosmological coupling of nonsingular black holes
• Constraints on the cosmological coupling of black holes from Gaia
• Strong Cosmic Censorship in light of Weak Gravity Conjecture for Charged Black Holes
• Constraints on the Cosmological Coupling of Black Holes from the Globular Cluster NGC 3201
• DESI Dark Energy Time Evolution is Recovered by Cosmologically Coupled Black Holes
• Constraints on Supermassive Black Hole Binaries from JWST and NANOGrav
• 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
• Exploring Proxies for the Supermassive Black Hole Mass Function: Implications for Pulsar Timing Arrays
• Black hole event horizons are cosmologically coupled
• Can gravitational vacuum condensate stars be a dark energy source?
• Constraints on cosmologically coupled black holes from gravitational wave observations and minimal formation mass
• f(R) Gravity in an Ellipsoidal Universe
• Observational implications of cosmologically coupled black holes
• Well-defined equations of motion without constraint of external sources

Cited by in corpus (7)

• Importance of being nonminimally coupled: Scalar Hawking radiation from regular black holes
• Topological regular black holes without Cauchy horizon
• Primordial regular black holes as all the dark matter. III. Covariant canonical quantum gravity models
• Dark Matter Spike surrounding Supermassive Black Holes Binary and the Nanohertz Stochastic Gravitational Wave Background
• Implications of pulsar timing arrays for Gauss-Bonnet Inflation
• Thermodynamically massless Simpson-Visser black holes
• Testing No slip model with pulsar timing arrays: NANOGrav and IPTA