Models of wave-function collapse, underlying theories, and experimental tests, Rev. Mod. Phys

Quantum mechanics is an extremely suc-cessful theory that agrees with every ex-periment. However, the principle of linear superposition, a central tenet of the the-ory, apparently contradicts a commonplace observation: macroscopic objects are never found in a linear superposition of position states. Moreover, the theory does not ex-plain why during a quantum measurement, deterministic evolution is replaced by prob-abilistic evolution, whose random outcomes obey the Born probability rule. In this article we review an experimentally falsifiable phe-nomenological proposal, known as Continu-ous Spontaneous Collapse: a stochastic non