ELECTRONIC JOURNAL OF DIFFERENTIAL EQUATIONS, 2013 (SCI-Expanded)
In this work, we describe all selfadjoint extensions of the minimal operator generated by linear singular multipoint symmetric differential expression l = (l(1), l(2), l(3)), l(k) = i d/dt + A(k) with selfadjoint operator coefficients A(k), k = 1, 2, 3 in a Hilbert space. This is done as a direct sum of Hilbert spaces of vector-functions