Li. Danilov, RESOLVENT ESTIMATES AND SPECTRUM OF THE DIRAC OPERATOR WITH PERIODIC POTENTIAL, Theoretical and mathematical physics, 103(1), 1995, pp. 349-365
Some estimates are given of the norm of the resolvent of the Dirac ope
rator on an n-dimensional torus (n greater than or equal to 2) for com
plex values of the quasimomentum. It is shown that the spectrum of the
periodic Dirac operator with potential V is an element of L(loc)(beta
)(R(3)), beta > 3, is absolutely continuous.