Spectral Theory of Elliptic Operators in Exterior Domains

Fritz Gesztesy, Mark M. Malamud

We consider various closed (and self-adjoint) extensions of elliptic differential expressions of the type $\cA=\sum_{0\le |α|,|β|\le m}(-1)^αD^αa_{α, β}(x)D^β$, $a_{α, β}(\cdot)\in…