Testing Gravity with Pulsar Scintillation Measurements

TL;DR

This paper proposes using pulsar scintillation measurements, which offer significantly improved timing accuracy, to test alternative gravity theories and detect gravitational waves at mHz frequencies.

Contribution

It introduces a novel method leveraging pulsar scintillation data to enhance sensitivity in testing gravity and gravitational waves, surpassing previous techniques.

Findings

Scintillation measurements improve timing accuracy by a factor of 10^5.

Sensitive to mHz gravitational waves, enabling new tests of gravity.

Potential to significantly tighten constraints on scalar gravitational-wave backgrounds.

Abstract

We propose to use pulsar scintillation measurements to test predictions of alternative theories of gravity. Comparing to single-path pulsar timing measurements, the scintillation measurements can achieve a factor of 10^5 improvement in timing accuracy, due to the effect of multi-path interference. Previous scintillation measurements of PSR B0834+06 have data acquisition for hours, making this approach sensitive to mHz gravitational waves. Therefore it has unique advantages in measuring gravitational effect or other mechanisms (at mHz and above frequencies) on light propagation. We illustrate its application in constraining scalar gravitational-wave background, in which case the sensitivities can be greatly improved with respect to previous limits. We expect much broader applications in testing gravity with existing and future pulsar scintillation observations.