2015/08/04 by Veliev, O. A. · 1 citation
#FOS: Mathematics #Spectral Theory (math.SP)
paper · doi:10.48550/arxiv.1508.00804
In this paper we construct the spectral expansion for the differential operator generated in all real line by ordinary differential expression of arbitrary order with periodic complex-valued coefficients by introducing new concepts as essential spectral singularities and singular quasimomenta and using the series with parenthesis. Moreover, we find a criteria for which the spectral expansion coincides with the Gelfand expansion for the self-adjoint case.