Eigenfunction Expansion Of The Dirac Eigenvalue Problem In The Case Of A Periodic Potential

The Sturm-Louville eigenvalue problem in the case of a periodic potentialhas its Floquet theory. By resorting to Titchmarsh formula and Floquet theory, the eigen-function expansion formula has been obtained.The Titchmarsh formula of the Dirac equation in the case of a periodic potentialis obtained in this paper. By resorting to its Floquet Theory , we obtain the result whichis simila to the result of the Sturm-Louville eigenvalue problem in the case of a periodicpotential.