Optimal strategies for gravitational wave stochastic background searches in pulsar timing data

TL;DR

This paper develops optimal detection techniques for gravitational wave stochastic backgrounds using pulsar timing arrays, adapting methods from interferometric data analysis to improve sensitivity and data interpretation.

Contribution

It introduces the optimal statistical methods for detecting gravitational wave backgrounds with pulsar timing data, including skymap construction and upper limit setting.

Findings

Neglecting pulsar metric perturbation effects is generally acceptable.

The optimal statistic enhances detection sensitivity.

Methods for realistic data analysis are discussed.

Abstract

A low frequency stochastic background of gravitational waves may be detected by pulsar timing experiments in the next five to ten years. Using methods developed to analyze interferometric gravitational wave data, in this paper we lay out the optimal techniques to detect a background of gravitational waves using a pulsar timing array. We show that for pulsar distances and gravitational wave frequencies typical of pulsar timing experiments, neglecting the effect of the metric perturbation at the pulsar does not result in a significant deviation from optimality. We discuss methods for setting upper limits using the optimal statistic, show how to construct skymaps using the pulsar timing array, and consider several issues associated with realistic analysis of pulsar timing data.