Nano-Hertz Gravitational Waves Searches with Interferometric Pulsar Timing Experiments

TL;DR

This paper proposes an interferometric pulsar timing method using two neighboring radio telescopes to cancel clock noise, significantly improving sensitivity to nano-Hertz gravitational waves in the 10^-9 to 10^-8 Hz band.

Contribution

It introduces a novel interferometric technique for pulsar timing that enhances gravitational wave detection sensitivity by canceling clock noise using paired telescopes.

Findings

Potential to improve sensitivity by nearly two orders of magnitude.

Applicable to upcoming large arraying projects.

Effective in the nano-Hertz frequency band.

Abstract

We estimate the sensitivity to nano-Hertz gravitational waves of pulsar timing experiments in which two highly-stable millisecond pulsars are tracked simultaneously with two neighboring radio telescopes that are referenced to the same time-keeping subsystem (i.e. "the clock"). By taking the difference of the two time-of-arrival residual data streams we can exactly cancel the clock noise in the combined data set, thereby enhancing the sensitivity to gravitational waves. We estimate that, in the band ($10^{-9} - 10^{-8}$) Hz, this "interferometric" pulsar timing technique can potentially improve the sensitivity to gravitational radiation by almost two orders of magnitude over that of single-telescopes. Interferometric pulsar timing experiments could be performed with neighboring pairs of antennas of the forthcoming large arraying projects.