2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93197The hilbert-space structure of quantum mechanics is related to the causal structure of space-time. The usual measurement hypotheses apparently preclude nonlinear or stochastic quantum evolution. By admitting a difference in the calculus of joint probabilities of events in space-time according to whether the separation is space-like or time-like, a relativistic nonlinear or stochastic quantum theory may be possible.10 pages, LaTeX. A resumed version to come out in the proceedings of the Internationa Symposium "Nonlinear, Dissipative, Irreversible Quantum Systems - Foundations, Examples and Experiments" August 15-19, 1994, Clausthal, GermanyQuantum PhysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext