Electronic Journal of Differential Equations,
Vol. 2013 (2013), No. 129, pp. 1-11.
Title: Selfadjoint extensions of a singular multipoint differential operator
of first order
Authors: Zameddin I. Ismailov (Karadeniz Technical Univ., Trabzon, Turkey)
Rukiye Ozturk Mert (Hitit Univ., Corum, Turkey)
Abstract:
In this work, we describe all selfadjoint extensions of the minimal
operator generated by linear singular multipoint symmetric differential
expression $l=(l_1,l_2,l_3)$, $l_k=i\frac{d}{dt}+A_k$ 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
$$
L_2(H,(-\infty ,a_1))\oplus L_2(H,(a_2,b_2))
\oplus L_2(H,(a_3,+\infty))
$$
where $-\infty