Scheme of a Derivation of Collapse from Quantum Dynamics II

Abstract: Is wave function collapse a prediction of the Schr\"odinger equation? This unusual problem is explored in an enlarged framework of interpretation, where quantum dynamics is considered exact and its interpretation is extended to include local entanglement of two systems, including a macroscopic one. This property of local entanglement, which results directly from the Schr\"odinger equation but is unrelated with observables, is measured by local probabilities, fundamentally distinct from quantum probabilities and evolving nonlinearly. When applied to a macroscopic system and the fluctuations in its environment, local entanglement can also inject a formerly ignored species of incoherence into the quantum state of this system,. When applied to a quantum measurement, the conjunction of these two effects suggests a self-consistent mechanism of collapse, which would directly derive from the Schr\"odinger equation. (This work develops and improves significantly a previously circulated version with the same title [23])