Boundary triplets, tensor products and point contacts to reservoirs

A. A. Boitsev, J. F. Brasche, M. M. Malamud +2

We consider symmetric operators of the form $S:=A\otimes I_{\mathfrak{T}}+I_{\mathfrak{H}}\otimes T$ where $A$ is symmetric and $T=T^{\ast }$ is (in general) unbounded. Such operato…