Locality Implies Complex Numbers in Quantum Mechanics
Quantum Physics
2026-04-14 v2
Abstract
We show that the presented real-number quantum theories, compatible with the independent source assumption, require the inclusion of a nonlocal map. This means that if the independent source assumption holds, in these models, complex-number quantum theory is equivalent to a real-number quantum theory with hidden nonlocal degrees of freedom. Our results suggest that complex numbers may be indispensable for describing the process involving entanglement between two independent systems.
Cite
@article{arxiv.2504.07808,
title = {Locality Implies Complex Numbers in Quantum Mechanics},
author = {Tianfeng Feng and Changliang Ren and Vlatko Vedral},
journal= {arXiv preprint arXiv:2504.07808},
year = {2026}
}
Comments
7 pages