ESO White Paper on Intensity Interferometry: Cosmology, Fundamental Physics, Quantum Optics

Robin Kaiser; William Guerin; Farrokh Vakili; Jean-Philippe Berger; Andrei Nomerotski; Sergei Kulkov; Peter Svihra; Eva Santos; Colin Carlile; Dainis Dravins; Stefan Funk; Prasenjit Saha; Roland Walter; Marcelo Borges Fernandes; Alex G. Kim; David Dunsky; Ken Van Tilburg; Masha Baryakhtar; Marios Galanis; Robert V. Wagoner; Neal Dalal; Junwu Huang; Charles Gammie; Norman W. Murray

arXiv · 2602.12717

ESO White Paper on Intensity Interferometry: Cosmology, Fundamental Physics, Quantum Optics

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Abstract

In this whitepaper, we outline how recent technological advances and ongoing developments open qualitatively new science opportunities in cosmology, fundamental physics, and quantum astrophysics. First, intensity interferometry can contribute to one of the most foundational observables in cosmology: the expansion rate of the Universe. Its angular resolution allows it to resolve the angular extent of extragalactic objects such as supernovae or quasars; combined with a physical scale local to the source, this yields an angular diameter distance and hence a 'Hubble diagram'. Second, the nature of dark matter can be probed via the astrometric lensing signatures of tiny dark matter halos. Third, intensity interferometry gives direct access to second-order coherence properties of astrophysical emission, opening a window onto genuinely quantum aspects of astrophysical light.

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Robin Kaiser, William Guerin, Farrokh Vakili, Jean-Philippe Berger, Andrei Nomerotski, Sergei Kulkov, Peter Svihra, Eva Santos, Colin Carlile, Dainis Dravins, Stefan Funk, Prasenjit Saha, Roland Walter, Marcelo Borges Fernandes, Alex G. Kim, David Dunsky, Ken Van Tilburg, Masha Baryakhtar, Marios Galanis, Robert V. Wagoner, Neal Dalal, Junwu Huang, Charles Gammie, Norman W. Murray. 2026-02-13. ESO White Paper on Intensity Interferometry: Cosmology, Fundamental Physics, Quantum Optics. https://arxiv.org/abs/2602.12717

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