En. Dancer et J. Lopez-gomez, Semiclassical analysis of general second order elliptic operators on bounded domains, T AM MATH S, 352(8), 2000, pp. 3723-3742
In this work we ascertain the semiclassical behavior of the fundamental ene
rgy and the ground state of an arbitrary second order elliptic operator, no
t necessarily selfadjoint, on a bounded domain. Our analysis provides us wi
th substantial improvements of many previous results found in the context o
f quantum mechanics for C-infinity perturbations of the Laplacian.