English
Related papers

Related papers: Beyond the Hellings-Downs curve: Non-Einsteinian g…

200 papers

We perform a Bayesian search in the latest Pulsar Timing Array (PTA) datasets for a stochastic gravitational wave (GW) background sourced by curvature perturbations at scales $10^5~\text{Mpc}^{-1}\lesssim k\lesssim 10^8~\text{Mpc}^{-1}$.…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Virgile Dandoy , Valerie Domcke , Fabrizio Rompineve

We present the results of the search for an isotropic stochastic gravitational wave background (GWB) at nanohertz frequencies using the second data release of the European Pulsar Timing Array (EPTA) for 25 millisecond pulsars and a…

The Hellings-Downs (HD) correlation, which characterizes the signature of a stochastic gravitational wave background measured via Pulsar Timing Arrays (PTA), is derived using a harmonic formalism. This approach closely follows the framework…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Cyril Pitrou , Giulia Cusin

The nanohertz stochastic gravitational wave background (SGWB) is an excellent early universe laboratory for testing the fundamental properties of gravity. In this letter, we elucidate on the full potential of pulsar timing array (PTA) by…

General Relativity and Quantum Cosmology · Physics 2024-05-24 Reginald Christian Bernardo , Kin-Wang Ng

A stochastic gravitational-wave background (SGWB) is expected to be produced by the superposition of individually undetectable, unresolved gravitational-wave (GW) signals from cosmological and astrophysical sources. Such a signal can be…

General Relativity and Quantum Cosmology · Physics 2023-05-17 Federico De Lillo , Jishnu Suresh , Antoine Depasse , Magdalena Sieniawska , Andrew L. Miller , Giacomo Bruno

Multiple pulsar timing array (PTA) collaborations have recently reported the first detection of gravitational waves (GWs) of nanohertz frequencies. The signal is expected to be primarily sourced by inspiralling supermassive black hole…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-13 Gabriela Sato-Polito , Matias Zaldarriaga , Eliot Quataert

We investigate the cross-correlation between astrometric and timing-residual observables for distant sources, such as pulsars and galaxies, and equivalent observables for nearby solar system bodies. Using the unified spin-weighted formalism…

General Relativity and Quantum Cosmology · Physics 2025-10-31 Elias Fink , Carlo Contaldi , Giorgio Mentasti

By regularly monitoring the most stable millisecond pulsars over many years, pulsar timing arrays (PTAs) are positioned to detect and study correlations in the timing behaviour of those pulsars. Gravitational waves (GWs) from supermassive…

The millisecond pulsars, old-recycled objects spinning with high frequency $\mathcal{O}$ (kHz) sustaining the deformation from their spherical shape, may emit gravitational waves (GW). These are one of the potential candidates contributing…

General Relativity and Quantum Cosmology · Physics 2023-07-18 Deepali Agarwal , Jishnu Suresh , Vuk Mandic , Andrew Matas , Tania Regimbau

Searches for stochastic gravitational-wave backgrounds using pulsar timing arrays look for correlations in the timing residuals induced by the background across the pulsars in the array. The correlation signature of an isotropic,…

General Relativity and Quantum Cosmology · Physics 2015-03-30 Fredrick A. Jenet , Joseph D. Romano

We study whether the signal seen by pulsar timing arrays (PTAs) may originate from gravitational waves (GWs) induced by large primordial perturbations. Such perturbations may be accompanied by a sizeable primordial black hole (PBH)…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-16 Gabriele Franciolini , Antonio Junior Iovino , Ville Vaskonen , Hardi Veermae

We revisit the theoretical modeling and simulation of a Gaussian stochastic gravitational wave background (SGWB) signal in a pulsar timing array (PTA). We show that the correlation between Fourier components of pulsar timing residuals can…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Reginald Christian Bernardo , Kin-Wang Ng

Precision pulsar timing at the level of tens to hundreds of nanoseconds allows detection of nanohertz gravitational waves (GWs) from supermassive binary black holes (SMBBHs) at the cores of merging galaxies and, potentially, from exotic…

Instrumentation and Methods for Astrophysics · Physics 2019-03-25 J. M. Cordes , M. A. McLaughlin

Pulsars are very stable clocks in space which have many applications to problems in physics and astrophysics. Observations of double-neutron-star binary systems have given the first observational evidence for the existence of gravitational…

High Energy Astrophysical Phenomena · Physics 2010-04-22 R. N. Manchester

Pulsar timing array experiments have recently found evidence for a stochastic gravitational wave (GW) background, which induces correlations among pulsar timing residuals described by the Hellings and Downs (HD) curve. Standard calculations…

General Relativity and Quantum Cosmology · Physics 2025-05-23 Nastassia Grimm , Martin Pijnenburg , Giulia Cusin , Camille Bonvin

Gravitational waves (GWs) are fluctuations in the fabric of spacetime predicted by Einstein's theory of general relativity. Using a collection of millisecond pulsars as high-precision clocks, the nanohertz band of this radiation is likely…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 P. Demorest , J. Lazio , A. Lommen

Recent pulsar timing array (PTA) experiments have reported strong evidence of the stochastic gravitational wave background (SGWB). If interpreted as primordial Gravitational Waves (pGWs), the signal favors a strongly blue-tilted spectrum.…

General Relativity and Quantum Cosmology · Physics 2025-02-12 Taotao Qiu , Mian Zhu

We search for isotropic stochastic gravitational-wave background (SGWB) in the International Pulsar Timing Array second data release. By modeling the SGWB as a power-law, we find very strong Bayesian evidence for a common-spectrum process,…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Zu-Cheng Chen , Yu-Mei Wu , Qing-Guo Huang

Pulsar Timing Array (PTA) observations have recently gathered substantial evidence for the existence of a gravitational wave background in the nHz frequency band. Searching for anisotropies in this signal is key to determining its origin,…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-02 Paul Frederik Depta , Valerie Domcke , Gabriele Franciolini , Mauro Pieroni

Statistical anisotropy in the nanohertz-frequency gravitational-wave background (GWB) is expected to be detected by pulsar timing arrays (PTAs) in the near future. By developing a frequentist statistical framework that intrinsically…

High Energy Astrophysical Phenomena · Physics 2022-12-14 Nihan Pol , Stephen R. Taylor , Joseph D. Romano