Strong lensing interferometry for compact binaries

TL;DR

This paper proposes a novel interferometric method leveraging strong gravitational lensing in pulsar binaries to enhance precision measurements of orbital parameters, gravitational wave background, and black hole spins.

Contribution

It introduces a new technique using multi-wavelength interferometry to analyze pulsar binaries with strong lensing effects, independent of pulse profile stability.

Findings

Potential to improve bounds on gravitational wave background

Method applicable to both slow and fast pulsars

Possibility of discovering suitable binaries with SKA

Abstract

We propose a possibility to improve the current precision measurements on compact binaries. When the orbital axis is almost perpendicular to our line of sight, a pulsar behind its companion can form two strong-lensing images. These images cannot be resolved, but we can use multi-wavelength interferometry to accurately determine the passage through superior conjunction. This method does not depend strongly on the stability of the pulse profile, and applies equally well to both slow and fast pulsars. We discuss the possible improvement this can bring to the bound on stochastic gravitational wave background and to determine black hole spin. We also discuss the possibility of discovering a suitable binary system by the Square Kilometer Array that our method can apply to.