Interferometric Parallax: A Method for Measurement of Astronomical Distances

TL;DR

This paper proposes a novel interferometric method to directly measure cosmological distances using 4-point correlations from well-separated detectors, potentially enabling measurements of Gigaparsec scale distances with upcoming space-based instruments.

Contribution

It introduces a new interferometric parallax technique based on 4-point amplitude and intensity correlations for direct cosmological distance measurement.

Findings

Distances of cosmological objects can be measured directly using interferometry.

Next-generation space detectors can achieve the baseline needed for Gigaparsec scale measurements.

Single photons can produce measurable correlations across astronomical distances.

Abstract

We show that distances of objects at cosmological distances can be measured directly using interferometry. Our approach to interferometric parallax comes from analysis of 4-point amplitude and intensity correlations that can be generated from pairs of well-separated detectors. The baseline required to measure cosmological distances of Gigaparsec order are within the reach of the next generation of space-borne detectors. The semi-classical interpretation of intensity correlations uses a notion of a single photon taking two paths simultaneously. Semi-classically a single photon can simultaneously enter four detectors separated by an astronomical unit, developing correlations feasible to measure with current technology.