Status Report on Global Pulsar-Timing-Array Efforts to Detect Gravitational Waves

TL;DR

This paper reviews the progress of pulsar timing arrays in detecting nanohertz gravitational waves, highlighting recent sensitivity improvements, ongoing research efforts, and astrophysical interpretations of recent gravitational wave estimates.

Contribution

It provides a comprehensive overview of current pulsar timing array efforts, summarizing recent advancements and the state of gravitational wave detection in this field.

Findings

Current sensitivity levels to gravitational waves

Recent progress in pulsar timing techniques

Astrophysical interpretations of gravitational wave data

Abstract

The stability of the spin of pulsars and the precision with which these spins can be determined, allows many unique tests of interest to physics and astrophysics. Perhaps the most challenging and revolutionary of these, is the detection of nanohertz gravitational waves. An increasing number of efforts to detect and study long-period gravitational waves by timing an array of pulsars have been ongoing for several decades and the field is moving ever closer to actual gravitational-wave science. In this review article, we summarise the state of this field by presenting the current sensitivity to gravitational waves and by reviewing recent progress along the multiple lines of research that are part of the continuous push towards greater sensitivity. We also briefly review some of the most recent efforts at astrophysical interpretation of the most recent GW estimates derived from pulsar timing.