The NANOGrav 15-year Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational Wave Background

Abstract

The NANOGrav 15-year data set shows evidence for the presence of a low-frequency gravitational-wave background (GWB). While many physical processes can source such low-frequency gravitational waves, here we analyze the signal as coming from a population of supermassive black hole (SMBH) binaries distributed throughout the Universe. We show that astrophysically motivated models of SMBH binary populations are able to reproduce both the amplitude and shape of the observed low-frequency gravitational-wave spectrum. While multiple model variations are able to reproduce the GWB spectrum at our current measurement precision, our results highlight the importance of accurately modeling binary evolution for producing realistic GWB spectra. Additionally, while reasonable parameters are able to reproduce the 15-year observations, the implied GWB amplitude necessitates either a large number of parameters to be at the edges of expected values, or a small number of parameters to be notably different from standard expectations. While we are not yet able to definitively establish the origin of the inferred GWB signal, the consistency of the signal with astrophysical expectations offers a tantalizing prospect for confirming that SMBH binaries are able to form, reach sub-parsec separations, and eventually coalesce. As the significance grows over time, higher-order features of the GWB spectrum will definitively determine the nature of the GWB and allow for novel constraints on SMBH populations.

arXiv commentAccepted by Astrophysical Journal Letters as part of Focus on NANOGrav's 15-year Data Set and the Gravitational Wave Background. For questions or comments, please email [email protected]. Edited to fix two equation typos (Eq.13 & 21), and minor text typos

References in corpus (155)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• The many lives of active galactic nuclei: cooling flows, black holes and the luminosities and colours of galaxies
• A Relationship Between Nuclear Black Hole Mass and Galaxy Velocity Dispersion
• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• Energy input from quasars regulates the growth and activity of black holes and their host galaxies
• Observational Evidence of AGN Feedback
• The slope of the black-hole mass versus velocity dispersion correlation
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• The Relation between Black Hole Mass, Bulge Mass, and Near-Infrared Luminosity
• On the Black Hole Mass - Bulge Mass Relation
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• The M-sigma and M-L Relations in Galactic Bulges and Determinations of their Intrinsic Scatter
• Revisiting the Scaling Relations of Black Hole Masses and Host Galaxy Properties
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• The Assembly and Merging History of Supermassive Black Holes in Hierarchical Models of Galaxy Formation
• The NANOGrav 15-year Data Set: Search for Signals from New Physics
• The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background
• High Proper Motion Stars in the Vicinity of Sgr A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy
• Formation of Galactic Nuclei
• Measuring gravitational waves from binary black hole coalescences: I. Signal to noise for inspiral, merger, and ringdown
• The stochastic gravitational-wave background from massive black hole binary systems: implications for observations with Pulsar Timing Arrays
• A Direct Measurement of Major Galaxy Mergers at z < 3
• Galaxy Stellar Mass Functions from ZFOURGE/CANDELS: An Excess of Low-Mass Galaxies Since z=2 and the Rapid Buildup of Quiescent Galaxies
• A Compact Supermassive Binary Black Hole System
• Gravitational Waves Probe the Coalescence Rate of Massive Black Hole Binaries
• Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA*
• Evolution of massive binary black holes
• Dynamical Friction and Galaxy Merging Timescales
• The NANOGrav 11-year Data Set: Pulsar-timing Constraints On The Stochastic Gravitational-wave Background
• The NANOGrav 15-year Data Set: Observations and Timing of 68 Millisecond Pulsars
• Binary Black Hole Accretion From a Circumbinary Disk: Gas Dynamics Inside the Central Cavity
• Low-Frequency Gravitational Waves from Massive Black Hole Binaries: Predictions for LISA and Pulsar Timing Arrays
• The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background
• On the evidence for a common-spectrum process in the search for the nanohertz gravitational-wave background with the Parkes Pulsar Timing Array
• Bulge Growth and Quenching since z = 2.5 in CANDELS/3D-HST
• The Population of Viscosity- and Gravitational Wave-Driven Supermassive Black Hole Binaries Among Luminous AGN
• The Role of Gas in the Merging of Massive Black Holes in Galactic Nuclei. II. Black Hole Merging in a Clumpy Disk
• A systematic search for close supermassive black hole binaries in the Catalina Real-Time Transient Survey
• Low-frequency gravitational radiation from coalescing massive black hole binaries in hierarchical cosmologies
• Efficient Merger of Binary Supermassive Black Holes in Non-Axisymmetric Galaxies
• False periodicities in quasar time-domain surveys
• The Astrophysics of Nanohertz Gravitational Waves
• The SINFONI Black Hole Survey: The Black Hole Fundamental Plane revisited and the paths of (co-) evolution of supermassive black holes and bulges
• Massive Black Hole Binary Evolution
• Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search
• Gravitational waves from resolvable massive black hole binary systems and observations with Pulsar Timing Arrays
• Supermassive black hole binaries in gaseous and stellar circumnuclear discs: orbital dynamics and gas accretion
• Ultra-Low Frequency Gravitational Radiation from Massive Black Hole Binaries
• The Quest for Dual and Binary Supermassive Black Holes: A Multi-Messenger View
• A Population of Short-Period Variable Quasars from PTF as Supermassive Black Hole Binary Candidates
• Bulge mass is king: The dominant role of the bulge in determining the fraction of passive galaxies in the Sloan Digital Sky Survey
• Understanding Dual AGN Activation in the Nearby Universe
• Expected properties of the first gravitational wave signal detected with pulsar timing arrays
• Gravitational Waves from a Compact Star in a Circular, Inspiral Orbit, in the Equatorial Plane of a Massive, Spinning Black Hole, as Observed by LISA
• Massive Black Hole Binary Mergers in Dynamical Galactic Environments
• Hydrodynamics of circumbinary accretion: Angular momentum transfer and binary orbital evolution
• The Structures of Distant Galaxies I: Galaxy Structures and the Merger Rate to z~3 in the Hubble Ultra-Deep Field
• Efficient Merger of Binary Supermassive Black Holes in Merging Galaxies
• Systematic investigation of the expected gravitational wave signal from supermassive black hole binaries in the pulsar timing band
• Inspiralling Supermassive Black Holes: A New Signpost for Galaxy Mergers
• Relativistic boost as the cause of periodicity in a massive black-hole binary candidate
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• The Merger History of Supermassive Black Holes in Galaxies
• Dynamics of triple black hole systems in hierarchically merging massive galaxies
• The Local Nanohertz Gravitational-Wave Landscape From Supermassive Black Hole Binaries
• The Gravitational Wave Background from Massive Black Hole Binaries in Illustris: spectral features and time to detection with pulsar timing arrays
• The structures and total (minor + major) merger histories of massive galaxies up to z = 3 in the HST GOODS NICMOS Survey: A possible solution to the size evolution problem
• Gas driven massive black hole binaries: signatures in the nHz gravitational wave background
• The NANOGrav 12.5 yr Data Set: Observations and Narrowband Timing of 47 Millisecond Pulsars
• The NANOGrav 15-Year Data Set: Detector Characterization and Noise Budget
• Self consistent model for the evolution of eccentric massive black hole binaries in stellar environments: implications for gravitational wave observations
• Hydrodynamic Torques in Circumbinary Accretion Disks
• Scattering experiments meet N-body I: a practical recipe for the evolution of massive black hole binaries in stellar environments
• Gravitational Waves from Supermassive Black Hole Coalescence in a Hierarchical Galaxy Formation Model
• Orbital Evolution of Equal-mass Eccentric Binaries due to a Gas Disk: Eccentric Inspirals and Circular Outspirals
• A Radio Census of Binary Supermassive Black Holes
• Black hole mergers from dwarf to massive galaxies with the NewHorizon and Horizon-AGN simulations
• Astrophysics Milestones For Pulsar Timing Array Gravitational Wave Detection
• Dynamical Friction around Supermassive Black Holes
• A consistent measure of the merger histories of massive galaxies using close-pair statistics I: Major mergers at $z<3.5$
• Single Sources in the Low-Frequency Gravitational Wave Sky: properties and time to detection by pulsar timing arrays
• Electromagnetic Counterparts to Massive Black Hole Mergers
• Long-Term Profile Variability of Double Peaked Emission Lines in Active Galactic Nuclei
• Super-massive binary black holes and emission lines in active galactic nuclei
• Insights on the astrophysics of supermassive black hole binaries from pulsar timing observations
• Equilibrium eccentricity of accreting binaries
• Constraining sub-Parsec Binary Supermassive Black Holes in Quasars with Multi-Epoch Spectroscopy. I. The General Quasar Population
• 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
• Supermassive Black Hole Binary Candidates from the Pan-STARRS1 Medium Deep Survey
• Interactions between multiple supermassive black holes in galactic nuclei: a solution to the final parsec problem
• Constraining the Orbit of Supermassive Black Hole Binary 0402+379
• Massive Close Pairs Measure Rapid Galaxy Assembly in Mergers at High Redshift
• Mining Gravitational-wave Catalogs To Understand Binary Stellar Evolution: A New Hierarchical Bayesian Framework
• Quasi-Periodic Behavior of Mini-Disks in Binary Black Holes Approaching Merger
• Constraining astrophysical observables of Galaxy and Supermassive Black Hole Binary Mergers using Pulsar Timing Arrays
• Supermassive Black Holes and the Evolution of Galaxies
• Modeling the uncertainties of solar-system ephemerides for robust gravitational-wave searches with pulsar timing arrays
• Binary super-massive black hole environments diminish the gravitational-wave signal in the pulsar timing band
• Orbital Evolution of Binaries in Circumbinary Disks
• Gravitational waves and stalled satellites from massive galaxy mergers at z <= 1
• Post-Newtonian evolution of massive black hole triplets in galactic nuclei -- III. A robust lower limit to the nHz stochastic background of gravitational waves
• A Large Systematic Search for Close Supermassive Binary and Rapidly Recoiling Black Holes - III. Radial Velocity Variations
• Massive black hole binary systems and the NANOGrav 12.5 year results
• Post-Newtonian evolution of massive black hole triplets in galactic nuclei -- II. Survey of the parameter space
• Testing the binary hypothesis: pulsar timing constraints on supermassive black hole binary candidates
• Galaxy Rotation and Rapid Supermassive Black Hole Binary Coalescence
• Selection bias in dynamically-measured super-massive black hole samples: consequences for pulsar timing arrays
• Massive BH Binaries as Periodically-Variable AGN
• Detection of eccentric supermassive black hole binaries with pulsar timing arrays: Signal-to-noise ratio calculations
• Constraining the Solution to the Last Parsec Problem with Pulsar Timing
• Understanding black hole mass assembly via accretion and mergers at late times in cosmological simulations
• Offset Active Galactic Nuclei as Tracers of Galaxy Mergers and Supermassive Black Hole Growth
• Post-Newtonian Evolution of Massive Black Hole Triplets in Galactic Nuclei: I. Numerical Implementation and Tests
• Constraints On The Dynamical Environments Of Supermassive Black-hole Binaries Using Pulsar-timing Arrays
• Music from the heavens - Gravitational waves from supermassive black hole mergers in the EAGLE simulations
• Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): Hubble Space Telescope Discovers Double Quasars
• Efficient computation of the gravitational wave spectrum emitted by eccentric massive black hole binaries in stellar environments
• A Large Systematic Search for Close Supermassive Binary and Rapidly Recoiling Black Holes - II. Continued Spectroscopic Monitoring and Optical Flux Variability
• Dynamical evolution of cosmic supermassive binary black holes and their gravitational wave radiation
• Testing the relativistic Doppler boost hypothesis for supermassive black hole binary candidates
• Forecasting pulsar timing array sensitivity to anisotropy in the stochastic gravitational wave background
• The Structures of Distant Galaxies - IV: A New Empirical Measurement of the Time-Scale for Galaxy Mergers - Implications for the Merger History
• Constraints on Black Hole/Host Galaxy Co-evolution and Binary Stalling Using Pulsar Timing Arrays
• Pulsar Timing Constraints on the Fermi Massive Black-Hole Binary Blazar Population
• The NANOGrav 11-Year Data Set: Evolution of Gravitational Wave Background Statistics
• The nightmare scenario: measuring the stochastic gravitational-wave background from stalling massive black-hole binaries with pulsar-timing arrays
• A quasar-based supermassive black hole binary population model: implications for the gravitational-wave background
• The effect of differential accretion on the Gravitational Wave Background and the present day MBH Binary population
• Astrophysical constraints on massive black hole binary evolution from Pulsar Timing Arrays
• Insights into searches for anisotropies in the nanohertz gravitational-wave background
• The minimum and maximum gravitational-wave background from supermassive binary black holes
• Multi-Messenger Astrophysics with Pulsar Timing Arrays
• Targeting supermassive black hole binaries and gravitational wave sources for the pulsar timing array
• Cosmic variance in the nanohertz gravitational wave background
• Evolution Of Massive Black Hole Binaries In Rotating Stellar Nuclei: Implications For Gravitational Wave Detection
• Gravitational Wave Hotspots: Ranking Potential Locations of Single-Source Gravitational Wave Emission
• Testing the relativistic Doppler boost hypothesis for the binary candidate quasar PG1302-102 with multi-band Swift data
• Considerations for the Observability of Kinematically Offset Binary AGN
• Likelihood for Detection of Sub-parsec Supermassive Black Hole Binaries in Spectroscopic Surveys
• Exploring Proxies for the Supermassive Black Hole Mass Function: Implications for Pulsar Timing Arrays
• Gravitational waves from supermassive black hole binaries in ultra-luminous infrared galaxies
• The Search for Binary Supermassive Black Holes Amongst Quasars with Offset Broad Lines Using the Very Long Baseline Array
• Pulsar Timing Array Constraints on the Merger Timescale of Subparsec Supermassive Black Hole Binary Candidates
• Predictions for LISA and PTA based on SHARK galaxy simulations

Cited by in corpus (156)

• Cosmological phase transitions: from perturbative particle physics to gravitational waves
• The recent gravitational wave observation by pulsar timing arrays and primordial black holes: the importance of non-gaussianities
• Cosmological Background Interpretation of Pulsar Timing Array Data
• Probing the equation of state of the early Universe with pulsar timing arrays
• The Science of the Einstein Telescope
• First-order Phase Transition interpretation of PTA signal produces solar-mass Black Holes
• The Need For Speed: Rapid Refitting Techniques for Bayesian Spectral Characterization of the Gravitational Wave Background Using PTAs
• Have pulsar timing array methods detected a cosmological phase transition?
• Gravitational Waves from SMBH Binaries in Light of the NANOGrav 15-Year Data
• Implications of Pulsar Timing Array Data for Scalar-Induced Gravitational Waves and Primordial Black Holes: Primordial Non-Gaussianity $f_{\mathrm{NL}}$ Considered
• Superheavy quasi-stable strings and walls bounded by strings in the light of NANOGrav 15 year data
• Extreme mass-ratio inspirals in ultra-light dark matter
• Gravitational waves from first-order phase transitions in LISA: reconstruction pipeline and physics interpretation
• Scalar induced gravitational waves in light of Pulsar Timing Array data
• Can supercooled phase transitions explain the gravitational wave background observed by pulsar timing arrays?
• Confronting sound speed resonance with pulsar timing arrays
• NANOGrav spectral index $\gamma =3$ from melting domain walls
• Cosmological Interpretation for the Stochastic Signal in Pulsar Timing Arrays
• Did we hear the sound of the Universe boiling? Analysis using the full fluid velocity profiles and NANOGrav 15-year data
• Induced Gravitational Wave interpretation of PTA data: a complete study for general equation of state
• NANOGrav signal from axion inflation
• Scalar induced gravity waves from ultra slow-roll Galileon inflation
• Probing The Early Universe Cosmology With NANOGrav: Possibilities and Limitations
• The NANOGrav 15-year Gravitational-Wave Background Methods
• Long-term Evolution of Binary Orbits Induced by Circumbinary Disks
• Primordial non-Gaussianity as a saviour for PBH overproduction in SIGWs generated by Pulsar Timing Arrays for Galileon inflation
• Ultra-low mass PBHs in the early universe can explain the PTA signal
• Gravitational waves induced by scalar-tensor mixing
• GA-NIFS: High number of dual active galactic nuclei at z~3
• Realisation of the ultra-slow roll phase in Galileon inflation and PBH overproduction
• Can the gravitational wave background feel wiggles in spacetime?
• Towards distinguishing Dirac from Majorana neutrino mass with gravitational waves
• Probing wave-optics effects and low-mass dark matter halos with lensing of gravitational waves from massive black holes
• Bounds on Ultralight Dark Matter from NANOGrav
• Practical approaches to analyzing PTA data: Cosmic strings with six pulsars
• From quantum gravity to gravitational waves through cosmic strings
• Large fluctuations and Primordial Black Holes
• Testing Realistic $SO(10)$ SUSY GUTs with Proton Decay and Gravitational Waves
• Search for Non-Tensorial Gravitational-Wave Backgrounds in the NANOGrav 15-Year Data Set
• Enhancement of gravitational waves at Q-ball decay including non-linear density perturbations
• Gravitational Wave Emission from a Cosmic String Loop, I: Global Case
• Implications of the pulsar timing array detections for massive black hole mergers in the LISA band
• A unified accretion disc model for supermassive black holes in galaxy formation simulations: method and implementation
• Probing Stochastic Gravitational Wave Background from $SU(5)\times U(1{)}_{\chi }$ Strings in Light of NANOGrav 15-Year Data
• Imprints of Supermassive Black Hole Evolution on the Spectral and Spatial Anisotropy of Nano-Hertz Stochastic Gravitational-Wave Background
• Constraints on Supermassive Black Hole Binaries from JWST and NANOGrav
• Dissecting the Stochastic Gravitational Wave Background with Astrometry
• Induced Gravitational Waves probing Primordial Black Hole Dark Matter with Memory Burden
• Constraints on holographic QCD phase transitions from PTA observations
• Unraveling the early universe's equation of state and primordial black hole production with PTA, BBN, and CMB observations
• Revisiting evolution of domain walls and their gravitational radiation with CosmoLattice
• Spectral Variance in a Stochastic Gravitational-Wave Background From a Binary Population
• Searching for High Frequency Gravitational Waves with Phonons
• Obviating PBH overproduction for SIGWs generated by Pulsar Timing Arrays in loop corrected EFT of bounce
• Implications of cosmologically coupled black holes for pulsar timing arrays
• Prospects for Taiji to detect a gravitational-wave background from cosmic strings
• Source anisotropies and pulsar timing arrays
• Status Report on Global Pulsar-Timing-Array Efforts to Detect Gravitational Waves
• Searching For Stochastic Gravitational Waves Below a Nanohertz
• Astrophysical neutrino oscillations after pulsar timing array analyses
• The NANOGrav 15 yr Data Set: Looking for Signs of Discreteness in the Gravitational-wave Background
• The NANOGrav 12.5-year data set: A computationally efficient eccentric binary search pipeline and constraints on an eccentric supermassive binary candidate in 3C 66B
• How to Detect an Astrophysical Nanohertz Gravitational-Wave Background
• Magnetically Arrested Circumbinary Accretion Flows
• RABBITS -- I. The crucial role of nuclear star formation in driving the coalescence of supermassive black hole binaries
• Spatial and Spectral Characterization of the Gravitational-wave Background with the PTA Optimal Statistic
• Reliable Identification of Binary Supermassive Black Holes from Rubin Observatory Time-Domain Monitoring
• Consistency of JWST Black Hole Observations with NANOGrav Gravitational Wave Measurements
• Regularized-Renormalized-Resummed loop corrected power spectrum of non-singular bounce with Primordial Black Hole formation
• A nonperturbative test of nucleation calculations for strong phase transitions
• Posterior predictive checking for gravitational-wave detection with pulsar timing arrays: I. The optimal statistic
• Untangling PBH overproduction in $w$-SIGWs generated by Pulsar Timing Arrays for MST-EFT of single field inflation
• Gravitational waves from low-scale cosmic strings
• Distinctive GWBs from eccentric inspiraling SMBH binaries with a DM spike
• Primordial Black Holes from Effective Field Theory of Stochastic Single Field Inflation at NNNLO
• Templated Anisotropic Analyses of the LISA Galactic Foreground
• Probing supermassive black hole seed scenarios with gravitational wave measurements
• Fast Likelihood-free Reconstruction of Gravitational Wave Backgrounds
• RABBITS -- II. The impact of AGN feedback on coalescing supermassive black holes in disc and elliptical galaxy mergers
• AsterX: a new open-source GPU-accelerated GRMHD code for dynamical spacetimes
• Sub-GeV dark matter and nano-Hertz gravitational waves from a classically conformal dark sector
• The Green Bank North Celestial Cap Survey IX: Timing Follow-up for 128 Pulsars
• Detectability of stochastic gravitational wave background from weakly hyperbolic encounters
• Solving the PTA Data Analysis Problem with a Global Gibbs Scheme
• Primordial Black Holes without fine-tuning from a light stochastic spectator field
• Negative non-Gaussianity as a salvager for PBHs with PTAs in bounce
• Constraining string cosmology with the gravitational-wave background using the NANOGrav 15-year data set
• Neural Networks unveiling the properties of gravitational wave background from massive black hole binaries
• Muffled Murmurs: Environmental effects in the LISA stochastic signal from stellar-mass black hole binaries
• Efficient Bayesian inference and model selection for continuous gravitational waves in pulsar timing array data
• A catalogue of candidate milli-parsec separation massive black hole binaries from long term optical photometric monitoring
• Thermodynamical uncertainties for primordial black holes from cosmological phase transitions
• Implications of Pulsar Timing Array Results for High Frequency Gravitational Waves
• Primordial Black-Hole-Based Pathways to Little Red Dots
• Posterior predictive checking for gravitational-wave detection with pulsar timing arrays: II. Posterior predictive distributions and pseudo Bayes factors
• A novel probe of graviton dispersion relations at nano-Hertz frequencies
• Memory of a Random Walk: Astrometric deflections from gravitational wave memory accumulation over cosmological scales
• Dark Matter Spike surrounding Supermassive Black Holes Binary and the Nanohertz Stochastic Gravitational Wave Background
• Choosing suitable noise models for nanohertz gravitational-wave astrophysics
• Premature supermassive black hole mergers in cosmological simulations of structure formation
• Signatures of Massive Black Hole Merger Host Galaxies from Cosmological Simulations II: Unique Stellar Kinematics in Integral Field Unit Spectroscopy
• Forecast Analysis of Astrophysical Stochastic Gravitational Wave Background beyond general relativity: A Case Study on Brans-Dicke Gravity
• Improving the detection sensitivity to primordial stochastic gravitational waves with reduced astrophysical foregrounds. II. Subthreshold binary neutron stars
• Probing Self-Interacting Dark Matter via Gravitational-Wave Background from Eccentric Supermassive Black Hole Mergers
• Hot, cold, and multi-component accretion flows around supermassive black hole binaries
• Implications for Pulsar Timing Arrays of Sub-solar Black Hole Detections: From LVK to Einstein Telescope and Cosmic Explorer
• Quantum-Ordering Ambiguities in Weak Chern-Simons 4D Gravity and Metastability of the Condensate-Induced Inflation
• Inferring Mbh-Mbulge Evolution from the Gravitational Wave Background
• Can the NANOGrav observations constrain the geometry of the universe?
• Gravitational wave energy momentum-tensor in reduced Horndeski theories
• The NANOGrav 15 yr data set: Posterior predictive checks for gravitational-wave detection with pulsar timing arrays
• Impact of primordial black holes on the formation of the first stars and galaxies
• Pulsar timing and polarimetry: results and perspectives
• Constraining inflation with nonminimal derivative coupling with the Parkes Pulsar Timing Array third data release
• Dynamical Lensing Tomography of Black Hole Ringdown
• Reconciling PTA and JWST and preparing for LISA with POMPOCO: a Parametrisation Of the Massive black hole POpulation for Comparison to Observations
• On Variation of Light Curves and Broad Emission Lines for Periodic QSOs from co-rotating Supermassive binary black holes in elliptical orbits
• Can asteroid-mass PBHDM be compatible with catalyzed phase transition interpretation of PTA?
• Reconstructing the LISA massive black hole binary population via iterative kernel density estimation
• Statistics of the supermassive black hole gravitational wave background anisotropy
• Supercooled Dark Scalar Phase Transitions explanation of NANOGrav data
• On the anisotropies of the cosmological gravitational-wave background from pulsar timing array observations
• Astrophysical and relativistic modeling of the recoiling black-hole candidate in quasar 3C 186
• Probing the mass relation between supermassive black holes and dark matter halos at high redshifts by gravitational wave experiments
• Probing Boson Clouds with Supermassive Black Hole Binaries
• The Host Galaxies of PTA Sources: Converting Supermassive BH Binary Parameters into EM Observables
• Inflation, Proton Decay and Gravitational Waves from Metastable Strings in $SU(4{)}_C\times SU(2{)}_L\times U(1{)}_R$ Model
• Constraints on ultra-slow-roll inflation with the NANOGrav 15-Year Dataset
• Non-linear effects on the Cosmological Gravitational Wave Background anisotropies
• Bright siren without electromagnetic counterpart by LISA-Taiji-TianQin network
• Anisotropy of Nanohertz Gravitational Wave Background and Source Clustering from Supermassive Binary Black Holes Based on Cosmological Simulation
• Exploring the anisotropic gravitational wave background from all-sky mock gravitational wave event catalogues
• Efficient prescription to search for linear gravitational wave memory from hyperbolic black hole encounters and its application to the NANOGrav 12.5-year dataset
• Self-Interacting Dark-Matter Spikes and the Final-Parsec Problem: Bayesian constraints from the NANOGrav 15-Year Gravitational-Wave Background
• Finite Populations & Finite Time: The Non-Gaussianity of a Gravitational Wave Background
• Multi-wavelength properties of $z\gtrsim 6$ LISA detectable events
• First Light And Reionization Epoch Simulations (FLARES) -- XIX: Supermassive black hole mergers in the early Universe and their environmental dependence
• Atacama Cosmology Telescope: Observations of supermassive black hole binary candidates. Strong sinusoidal variations at 95, 147 and 225 GHz in PKS 2131$-$021 and PKS J0805$-$0111
• High-Redshift Merger Model for Low-Frequency Gravitational Wave Background
• Primordial Black Holes from Spatially Varying Cosmological Constant Induced by Field Fluctuations in Extra Dimensions
• The NANOGrav 15 yr Data Set: Customized Chromatic Noise Models
• Identifying the Quadrupolar Nature of Gravitational Wave Background through Space-based Missions
• Stochastic gravitational wave background anisotropies from inflation with non-Bunch-Davies states
• Bayesian leave-one-out cross-validation for astrophysical model comparison using gravitational-wave background data
• Ultralight scalar dark matter versus nonadiabatic perfect fluid dark matter in pulsar timing
• Flattened bispectrum of the scalar-induced gravitational waves
• Gravitational Wave Measurement of the $M_{\mathrm{BH}}$-$M_{\mathrm{bulge}}$ Intrinsic Scatter at High Redshift
• Shadows of Giants: Constraints on Stupendously Large Black Holes from Negative Sources against the Cosmic Microwave Background
• Searching Stochastic Gravitational Wave Background Landscape Across Frequency Bands
• Assessing the performance of future space-based detectors: Astrophysical foregrounds and individual sources
• Stochastic gravitational wave background from the collisions of dark matter halos
• Time-dependent deflection reconstruction: new technique to search for gravitational waves with the cosmic microwave background
• Model-agnostic gravitational-wave background characterization algorithm
• Massive black holes in the first billion years with JWST
• A two-step strategy to identify episodic sources of gravitational waves and high energy neutrinos in starburst galaxies
• A Population Study for Searching Supermassive Binary Black Holes in Active Galactic Nuclei: Continuum Spectral Features and Periodic Variabilities