Sign-indefinite second order differential operators on finite metric graphs
arXiv:1211.4144 · doi:10.1142/S0129055X14300039
Abstract
The question of self-adjoint realizations of sign-indefinite second order differential operators is discussed in terms of a model problem. Operators of the type $-\frac{d}{dx} \sgn (x) \frac{d}{dx}$ are generalized to finite, not necessarily compact, metric graphs. All self-adjoint realizations are parametrized using methods from extension theory. The spectral and scattering theory of the self-adjoint realizations are studied in detail.
43 pages, 2 figures