Wave optics for rotating stars

TL;DR

This paper investigates wave optics gravitational lensing by rotating stars, revealing that the star's spin affects interference patterns and caustics, enabling potential measurement of the star's angular momentum.

Contribution

It provides a detailed analysis of wave optics effects in Lense-Thirring spacetime, correcting prior assumptions about the star's spin influence on lensing phenomena.

Findings

Star spin influences interference fringes and caustics

Interference patterns can be used to measure stellar spin

Contradicts previous literature assumptions

Abstract

Gravitational lensing in wave optics is a rich field combining caustic singularities, general relativity and interference phenomena. We present a detailed evaluation of wave optics effects resulting from the frame-dragging of a rotating star modeled by a Lense-Thirring spacetime. We demonstrate that, contrary to what was previously stated in the literature, the spin of the star leaves an intricate imprint on the interference fringes and the caustics of the lensed source. This interference pattern can in principle be used to directly measure the spin of the lens.