Malamud M. Problems of uniqueness, completeness and self-adjointness in boundary value problems for systems of differential equations.

In the thesis, theorem on the unique determination of a system of linear ordinary differential equations by its monodromy matrix is proved. In the selfadjoint case, it is proved the existence of triangular transformation operators. Conditions of the completeness of system of root vectors of general boundary value problems for systems of linear ordinary differential equations are found. It is solved the inverse problem from the spectral matrix function of a boundary value problem generated by a formally symmetric system of linear ordinary differential equations on the half-line. Conditions of self-adjointness both on the half-line and on the line of symmetric systems of the first and the second orders are found.