Understanding the gravitational-wave Hellings and Downs curve for pulsar timing arrays in terms of sound and electromagnetic waves

Authors

Fredrick A. Jenet, The University of Texas Rio Grande ValleyFollow
Joseph D. Romano, The University of Texas Rio Grande Valley

Document Type

Article

Publication Date

2015

Abstract

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, unpolarized gravitational-wave background predicted by general relativity follows the so-called Hellings and Downs curve, which is a relatively simple function of the angle between a pair of Earth-pulsar baselines. In this paper, we give a pedagogical discussion of the Hellings and Downs curve for pulsar timing arrays, considering simpler analogous scenarios involving sound and electromagnetic waves. We calculate Hellings-and-Downs-type functions for these two scenarios and develop a framework suitable for doing more general correlation calculations.

Comments

© 2015 American Association of Physics Teachers. Original published version available at http://dx.doi.org/10.1119/1.4916358

Recommended Citation

Jenet, Fredrick A., and Joseph D. Romano. “Understanding the Gravitational-Wave Hellings and Downs Curve for Pulsar Timing Arrays in Terms of Sound and Electromagnetic Waves.” American Journal of Physics, vol. 83, no. 7, American Association of Physics Teachers, June 2015, pp. 635–45, doi:10.1119/1.4916358.

Publication Title

American Journal of Physics

DOI

10.1119/1.4916358