  We propose a technical reformulation of the measurement problem of quantum
mechanics, which is based on the postulate that the final state of a
measurement is classical. Unlike the usual formulation (in which the
post-measurement state is a unit vector in Hilbert space), our version actually
opens the possibility of admitting a purely technical solution within the
confines of conventional quantum theory (as opposed to solutions that either
modify this theory, or introduce unusual and controversial interpretative rules
and/or ontologies). To that effect, we recall a remarkable phenomenon in the
theory of Schroedinger operators (discovered in 1981 by Jona-Lasinio et al),
according to which the ground state of a symmetric double-well Hamiltonian
becomes exponentially sensitive to tiny perturbations of the potential as h ->
0. We show that this instability emerges also from the textbook WKB
approximation, extend it to time-dependent perturbations, and study the
dynamical transition from the ground state of the double well to the perturbed
ground state (in which the cat is typically either dead or alive, depending on
the details of the perturbation). Numerical simulations show that adiabatically
arising perturbations may (quite literally) cause the collapse of the
wave-function in the classical limit. Thus, at least in the context of a simple
mathematical model, we combine the technical and conceptual virtues of
decoherence (which fails to solve the measurement problem but launches the key
idea that perturbations may come from the environment) with those of dynamical
collapse models a la GRW (which do solve the measurement problem but are ad
hoc), without sharing their drawbacks: single measurement outcomes are obtained
(instead of merely diagonal reduced density matrices), and no modification of
quantum mechanics is needed.
