Wave diffraction by a cosmic string

TL;DR

This paper proposes a method to identify cosmic strings through characteristic wave diffraction patterns, notably the Cornu spiral, using Keller's diffraction theory applicable to various massless waves.

Contribution

It introduces a novel approach to detect cosmic strings by analyzing wave diffraction patterns, extending the theory to scalar massless waves including gravitational and electromagnetic waves.

Findings

Diffraction patterns can reveal the presence of cosmic strings.

Wave effects in conical spacetime can be explained by interference of four characteristic rays.

The method applies to gravitational, electromagnetic, and analogous condensed matter waves.

Abstract

We show that if a cosmic string exists, it may be identified through characteristic diffraction pattern in the energy spectrum of the observed signal. In particular, if the string is on the line of sight, the wave field is shown to fit the Cornu spiral. We suggest a simple procedure, based on Keller's geometrical theory of diffraction, which allows to explain wave effects in conical spacetime of a cosmic string in terms of interference of four characteristic rays. Our results are supposed to be valid for scalar massless waves, including gravitational waves, electromagnetic waves, or even sound in case of condensed matter systems with analogous topological defects.