Test of the essential collapse-locality loophole

Quantum Physics [Submitted on 26 Mar 2026] Test of the essential collapse-locality loophole Mónica Agüero, Juliana Bourdieu, Alejandro Hnilo, Marcelo Kovalsky, Myriam Nonaka Collapse-locality is an untested loophole in the violation of Bell's inequalities. The core of the argument is that the time value of photon detection is delayed by the time Tc required by the collapse of its quantum state. The value of Tc is given by the underlying theory of quantum collapse, and is mostly unknown. Depending on the value of Tc, detections in the performed Bell's experiments may have not been truly space-like separated events. This implies that the inequalities may have been violated as a consequence of (conspiratorial) information propagating at subluminal speed. We report an optical Bell experiment which closes the weaker ('essential') form of this loophole regardless the theory of quantum collapse. This is possible thanks to unique features of the setup. These features are: classical signals sent to the stations to define a time reference, and variable distance between the stations leaving all other parameters constant. Comments: Main text with 5 pages, 3 figures, 1 table; Supplementary Information with 5 pages and 4 figures Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2603.24909 [quant-ph]   (or arXiv:2603.24909v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.24909 Focus to learn more Submission history From: Alejandro Hnilo Dr. [view email] [v1] Thu, 26 Mar 2026 00:47:32 UTC (600 KB) Access Paper: view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)