On the Spectrum of \(\boldsymbol {2\times 2} \) Dirac Operator with Degenerate Boundary Conditions

We study the spectral problem for Dirac operator with degenerate boundary conditionsand a complex-valued summable potential. Sufficient conditions are found under which thespectrum of the considered problem coincides with the spectrum of the corresponding unperturbedoperator. The paper also established the properties of the matrix of the fundamental solutionsystem to Dirac system.