The Spectral Theory of Periodic Differential Equations

an(t applied boundary conditions bounded Chapter closed coefficients complete consider constant COROLLARY corresponding defined denote derivatives differential equation differential operator Eastham eigenfunctions eigenvalue problems equality estimates example exists extension fact finite follows formula Fourier functions further gaps given gives Hence Hochstadt holds implies increases inequality infinite instability interval integral introduced involving least Lemma length Let p(x linear linearly independent Mam+1 matrix method multiplicity non-trivial solution obtain occurs particular period periodic problem piecewise continuous positive possible proof proof of Theorem properties proved proves the theorem real-valued references relation replaced respect result right-hand satisfy self-adjoint semi-periodic side similar Similarly simple situation solutions of 2.1.1 space spectrum stability intervals suppose Theorem theory Titchmarsh transformation unity values vector write written Yn(x yo(x zero