We give a self-contained presentation of the theory of self-adjoint extensions using the
technique of boundary triples. A description of the spectra of self-adjoint extensions in terms …

Small-radius tubular structures have attracted considerable attention in the last few years,
and are frequently used in different areas such as Mathematical Physics, Spectral Geometry …

The concepts of boundary relations and the corresponding Weyl families are introduced. Let
$ S $ be a closed symmetric linear operator or, more generally, a closed symmetric relation …

For a symmetric operator or relation A with infinite deficiency indices in a Hilbert space we
develop an abstract framework for the description of symmetric and self-adjoint extensions …

Self-adjoint Schrödinger operators with δ and δ′-potentials supported on a smooth
compact hypersurface are defined explicitly via boundary conditions. The spectral properties …

We provide a simple recipe for obtaining all self-adjoint extensions, together with their
resolvent, of the symmetric operator $ S $ obtained by restricting the self-adjoint operator …

This paper has two main goals. First, we are concerned with a description of all self-adjoint
extensions of the Laplacian-Δ| _ C_0^ ∞ (Ω) in L 2 (Ω; dnx). Here, the domain Ω belongs to …

Abstract The Kreĭn-Naĭmark formula provides a parametrization of all selfadjoint exit space
extensions of a (not necessarily densely defined) symmetric operator in terms of maximal …

arXiv:0803.3179v2 [math.AP] 15 May 2008 Page 1 arXiv:0803.3179v2 [math.AP] 15 May 2008
GENERALIZED ROBIN BOUNDARY CONDITIONS, ROBIN-TO-DIRICHLET MAPS, AND …

With a closed symmetric operator A in a Hilbert space H a triple Π={H, Γ 0, Γ 1} of a Hilbert
space H and two abstract trace operators Γ0 and Γ1 from A∗ to H is called a generalized …