Maximal-quasi-accretive Laplacians on finite metric graphs
  For a finite not necessarily compact metric graph, one considers the differential expression $-\frac{d^2}{d x^2}$ on each edge. The boundary conditions at the vertices of the graph yielding quasi-m-accretive as well as m-accretive operators are completely characterized. 
Amru Hussein
math.AP math-ph math.MP