Brown B.M., Eastham M., Schmidt K.M. Periodic Differential Operators

Birkhauser, 2012. — 226 pages. ISBN: 3034805276Periodic differential operators have a rich mathematical theory as well as important physical applications. They have been the subject of intensive development for over a century and remain a fertile research area. This book lays out the theoretical foundations and then moves on to give a coherent account of more recent results, relating in particular to the eigenvalue and spectral theory of the Hill and Dirac equations.