Related papers: The Second International Pulsar Timing Array Mock …
Pulsar timing arrays (PTAs) are on the verge of detecting low-frequency gravitational waves (GWs) from supermassive black hole binaries (SMBHBs). With continued observations of a large sample of millisecond pulsars, PTAs will reach this…
The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) is a collaboration of researchers who are actively engaged in using North American radio telescopes to detect and study gravitational waves via pulsar timing. To…
The Square Kilometre Array (SKA) is a planned multi purpose radio telescope with a collecting area approaching 1 million square metres. One of the key science objectives of the SKA is to provide exquisite strong-field tests of gravitational…
Massive black hole binary systems, with masses in the range ~10^4-10^10 \msun, are among the primary sources of gravitational waves in the frequency window ~10^-9 Hz - 0.1 Hz. Pulsar Timing Arrays (PTAs) and the Laser Interferometer Space…
In this talk I review how a non-zero cosmological constant $\Lambda$ affects the propagation of gravitational waves and their detection in pulsar timing arrays (PTA). If $\Lambda\neq 0$ it turns out that waves are anharmonic in cosmological…
We describe the design of a gravitational wave timing array, a novel scheme that can be used to search for low-frequency gravitational waves by monitoring continuous gravitational waves at higher frequencies. We show that observations of…
The use of pulsars as astrophysical clocks for gravitational wave experiments demands the highest possible timing precision. Pulse times of arrival (TOAs) are limited by stochastic processes that occur in the pulsar itself, along the line…
For pulsar timing arrays (PTAs), the telltale signature of an isotropic stochastic background of gravitational waves is a pattern of pairwise interpulsar timing correlations approximately following the Hellings & Downs (HD) curve. Certain…
We present results of an all-sky search in the Parkes Pulsar Timing Array (PPTA) Data Release 1 data set for continuous gravitational waves (GWs) in the frequency range from $5\times 10^{-9}$ to $2\times 10^{-7}$ Hz. Such signals could be…
Pulsar timing arrays (PTAs) are searching for gravitational waves from supermassive black hole binaries (SMBHBs). Here we show how future PTAs could use a detection of gravitational waves from individually resolved SMBHB sources to produce…
While observations of many high-precision radio pulsars of order $\lesssim1~\mu$s across the sky are needed for the detection and characterization of a stochastic background of low-frequency gravitational waves (GWs), sensitivity to single…
The existence of a stochastic gravitational wave background is indicated by the recent pulsar timing array (PTA) experiments. We study the enhanced production of second-order gravitational waves from the scalar perturbations when the…
Pulsar timing arrays (PTAs) are searching for nanohertz-frequency gravitational waves (GWs) through cross-correlation of pulse arrival times from a set of radio pulsars. PTAs have relied upon a frequency-shift formula of the pulse, where…
Pulsar Timing Arrays are playing a crucial role in the ongoing gravitational wave astronomy revolution. The current evidence for a stochastic gravitational wave background (SGWB) at nHz frequencies offers an opportunity to discover…
Supermassive black hole binaries are one of the primary targets for gravitational wave searches using pulsar timing arrays. Gravitational wave signals from such systems are well represented by parametrized models, allowing the standard…
Pulsar timing arrays are sensitive to gravitational wave perturbations produced by individual supermassive black hole binaries during their early inspiral phase. Modified gravity theories allow for the emission of gravitational dipole…
The measurement error of pulse times of arrival (TOAs) in the high S/N limit is dominated by the quasi-random variation of a pulsar's emission profile from rotation to rotation. Like measurement noise, this noise is only reduced as the…
Direct detection of gravitational waves by pulsar timing arrays will become feasible over the next few years. In the low frequency regime ($10^{-7}$ Hz -- $10^{-9}$ Hz), we expect that a superposition of gravitational waves from many…
Using public pulse time-of-arrival data from five pulsar timing arrays (PTAs), we search for a stationary, isotropic, and unpolarized nHz stochastic gravitational-wave background (SGWB). This analysis is more sensitive than previous…
We search for the isotropic stochastic gravitational-wave background, including the nontensorial polarizations that are allowed in general metric theories of gravity, in the Parkes Pulsar Timing Array (PPTA) second data release (DR2). We…