State updates and useful qubits in relativistic quantum information
Quantum Physics
2025-09-09 v2 General Relativity and Quantum Cosmology
High Energy Physics - Theory
Abstract
We address the longstanding challenge of consistently updating quantum states after selective measurements in a relativistic spacetime. Standard updates along the future lightcones preserve causality but break correlations between causally disconnected parties, whereas updates along the past lightcone either imply retrocausality or do not respect the causal propagation of information. We introduce a minimal extension of multipartite states to encode subsystem-specific contextual information. This "polyperspective" formalism ensures causally consistent covariant state updates, preserves multipartite correlations, and respects conservation laws.
Cite
@article{arxiv.2506.18906,
title = {State updates and useful qubits in relativistic quantum information},
author = {José Polo-Gómez and T. Rick Perche and Eduardo Martín-Martínez},
journal= {arXiv preprint arXiv:2506.18906},
year = {2025}
}
Comments
10 pages, 2 figures. RevTeX 4.2. v2: Revised explanations and terminology for clarity