Observing Gravitational Lenses from Intensity Fluctuations: Experimental Validation of the Technique

TL;DR

This paper experimentally validates a technique that uses intensity fluctuation spectra to observe gravitational lenses, confirming the importance of frequency-dependent correlation measurements for unresolved lens detection.

Contribution

It provides experimental confirmation that the correlation coefficient must be evaluated at fluctuation spectrum frequencies, validating a simple method for gravitational lens detection.

Findings

Correlation coefficient must be evaluated at fluctuation frequencies

Validation of the technique for unresolved gravitational lens detection

Supports further theoretical and observational studies

Abstract

It has been proposed to study gravitational lenses from measurements of the spectrum of the fluctuations of the output current of a quadratic detector. The spatial correlation coefficient of the source is the fundamental parameter of the technique. The experimental work discussed in this article confirms that the correlation coefficient must be evaluated at the frequencies of the spectrum of the current fluctuations. This validates a powerful yet simple technique to find unresolved gravitational lenses and to study the lensing event and the source. The validation is needed before starting the extensive theoretical and observational work that must now follow.