English
Related papers

Related papers: Variance of the Hellings-Downs Correlation

200 papers

A successful measurement of the Stochastic Gravitational Wave Background (SGWB) in Pulsar Timing Arrays (PTAs) would open up a new window through which to test the predictions of General Relativity (GR). We consider how these measurements…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-29 Qiuyue Liang , Meng-Xiang Lin , Mark Trodden

We describe an alternative approach to the analysis of gravitational-wave backgrounds, based on the formalism used to characterise the polarisation of the cosmic microwave background. In contrast to standard analyses, this approach makes no…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Jonathan R. Gair , Joseph D. Romano , Stephen Taylor , Chiara M. F. Mingarelli

Pulsar timing arrays act to detect gravitational waves by observing the small, correlated effect the waves have on pulse arrival times at Earth. This effect has conventionally been evaluated assuming the gravitational wave phasefronts are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Xihao Deng , Lee Samuel Finn

The stochastic gravitational wave background (SGWB) consists of an incoherent collection of waves from both astrophysical and cosmological sources. To distinguish the SGWB from noise, it is essential to verify its quadrupolar nature,…

General Relativity and Quantum Cosmology · Physics 2025-08-22 Yifan Chen , Yuxiang Liu , Jing Shu , Bin Xu , Xiao Xue , Yanjie Zeng

A gravitational-wave background can be detected in pulsar-timing-array data as Hellings--Downs correlations among the timing residuals measured for different pulsars. The optimal statistic implements this concept as a classical…

High Energy Astrophysical Phenomena · Physics 2024-02-14 Michele Vallisneri , Patrick M. Meyers , Katerina Chatziioannou , Alvin J. K. Chua

Gravitational waves astronomy has opened a new opportunity to study the Universe. Full exploitation of this window can especially be provided by combining data coming from gravitational waves experiments with luminous tracers of the Large…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 Giulio Scelfo , Lumen Boco , Andrea Lapi , Matteo Viel

Gravitational Waves (GWs) are tiny ripples in the fabric of space-time predicted by Einstein's General Relativity. Pulsar timing arrays (PTAs) are well poised to detect low frequency ($10^{-9}$ -- $10^{-7}$ Hz) GWs in the near future. There…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 J. A. Ellis , F. A. Jenet , M. A. McLaughlin

Very recently, several pulsar timing array collaborations, including CPTA, EPTA, and NANOGrav, reported their results from searches for an isotropic stochastic gravitational wave background (SGWB), with each finding positive evidence for…

High Energy Astrophysical Phenomena · Physics 2023-07-06 Ligong Bian , Shuailiang Ge , Jing Shu , Bo Wang , Xing-Yu Yang , Junchao Zong

Pulsar Timing Arrays (PTAs) have recently found strong evidence for low-frequency gravitational waves (GWs) in the nanohertz frequency regime. As GWs pass, they produce deviations in measured lengths and light-travel times. PTA experiments…

High Energy Astrophysical Phenomena · Physics 2025-05-05 Luke Zoltan Kelley

A new detection method for ultra-low frequency gravitational waves (GWs) with a frequency much lower than the observational range of pulsar timing arrays (PTAs) was suggested in Yonemaru et al. (2016). In the PTA analysis, ultra-low…

High Energy Astrophysical Phenomena · Physics 2018-05-02 Naoyuki Yonemaru , Hiroki Kumamoto , Keitaro Takahashi , Sachiko Kuroyanagi

Significant gravitational wave emission is expected from gamma-ray bursts arising from compact stellar mergers, and possibly also from bursts associated with fast-rotating massive stellar core collapses. These models have in common a high…

Astrophysics · Physics 2009-11-07 Shiho Kobayashi , Peter Meszaros

Recent pulsar timing array results, including the NANOGrav 15-year data set, show evidence for a stochastic gravitational-wave background (GWB) in the nanohertz band. We present a Bayesian framework to compare three possible origins: (i) a…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Mengshen Wang , Zuocheng Zhang , Hua Xu

A gravitational wave passing through a pulsar will lead to a variation in the moment of inertia of the pulsar affecting its rotation. This will affect the extremely accurately measured spin rate of the pulsar as well as its pulse profile…

High Energy Astrophysical Phenomena · Physics 2021-05-17 Arpan Das , Shreyansh S. Dave , Oindrila Ganguly , Ajit M. Srivastava

Crosscorrelation of the outputs of two Gravitational Wave (GW) detectors has recently been proposed [1] as a method for detecting statistical association between GWs and Gamma Ray Bursts (GRBs). Unfortunately, the method can be effectively…

Astrophysics · Physics 2009-11-07 G. Modestino , A. Moleti

The models currently used in the detection of gravitational waves (GWs) either do not consider a relative motion between the center-of-mass of the source and the observer, or usually only consider its effect on the frequencies of GWs.…

High Energy Astrophysical Phenomena · Physics 2020-04-28 Alejandro Torres-Orjuela , Xian Chen , Zhoujian Cao , Pau Amaro-Seoane , Peng Peng

Pulsar timing arrays aim to detect nanohertz-frequency gravitational waves (GWs). A background of GWs modulates pulsar arrival times and manifests as a stochastic process, common to all pulsars, with a signature spatial correlation. Here we…

In the nanohertz band, the spatial correlations in pulsar timing arrays (PTAs) produced by interfering gravitational waves (GWs) from multiple sources likely deviate from the traditional ones without interference under the assumption of an…

General Relativity and Quantum Cosmology · Physics 2025-10-01 Yu-Mei Wu , Yan-Chen Bi , Qing-Guo Huang

In this paper, we study the polarization of a gravitational wave (GW) emitted by an astrophysical source at a cosmic distance propagating through the Friedmann-Lema\^itre-Robertson-Walk universe. By considering the null geodesic deviations,…

General Relativity and Quantum Cosmology · Physics 2021-10-25 Jia-Xi Feng , Fu-Wen Shu , Anzhong Wang

In this paper, we systematically study gravitational waves (GWs) produced by remote compact astrophysical sources. To describe such GWs properly, we introduce three scales, $\lambda, \; L_c$ and $L$, denoting, respectively, the typical…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-30 Jared Fier , Xiongjun Fang , Bowen Li , Shinji Mukohyama , Anzhong Wang , Tao Zhu

Several mechanisms for gravitational wave (GW) emission are believed to be associated with pulsar glitches. This emission may be split between long duration continuous waves and short duration bursts. In the Advanced LIGO era, searches for…

High Energy Astrophysical Phenomena · Physics 2025-12-24 Matthew Ball , Raymond Frey