This book presents the basic methods and applications in semiclassical approximation in the light of developments.

This book presents the basic methods and applications in semiclassical approximation in the light of developments.

The prime goal of this monograph, which comprises a total of five volumes, is to derive sharp spectral asymptotics for broad classes of partial differential ope

"...A graduate level text introducing readers to semiclassical and microlocal methods in PDE." -- from xi.

The asymptotic distribution of eigenvalues of self-adjoint differential operators in the high-energy limit, or the semi-classical limit, is a classical subject