Causal Fermion Systems as an Effective Collapse Theory

TL;DR

This paper demonstrates that causal fermion systems can produce an effective collapse mechanism in quantum mechanics, deriving nonlinear, stochastic corrections to the Schrödinger equation and describing state dynamics with a Lindblad-type equation.

Contribution

It introduces a novel effective collapse model from causal fermion systems, connecting foundational quantum theory with a new dynamical collapse mechanism.

Findings

Derives nonlinear, stochastic corrections to Schrödinger equation

Shows the statistical operator follows a Lindblad-type dynamics

Proposes a collapse model compatible with the Born rule

Abstract

It is shown that, in the non-relativistic limit, causal fermion systems give rise to an effective collapse theory. The nonlinear and stochastic correction terms to the Schr\"odinger equation are derived from the causal action principle. The dynamics of the statistical operator is described by a deterministic equation of Kossakowski-Lindblad form. Moreover, the quantum state undergoes a dynamical collapse compatible with the Born rule. The effective model has similarities with the continuous spontaneous localization model, but differs from it by a conservation law for the probability integral as well as a non-locality in time on a microscopic length scale $\ell_{\min}$.