“…One of the goals of this paper is the determination of the deficiency index def L 0 = (k, l) of L 0 . Since we assume L to be regular at a, i.e., the coefficients are locally integrable on [a, ∞), the only possibilities are (2, 1), (2,2), or (3, 3) as discussed in Section 2. In the case of maximal deficiency index any selfadjoint extension H of L 0 has a Hilbert Schmidt resolvent.…”