# Reference for Neumann-Laplacian

Let $\Omega\subset R^d$ be a bounded, smooth domain. Consider $A=-\Delta$ subject to homogeneous Neumann boundary conditions in $L^p$-spaces. Does anybody know a good reference book on basic results like closedness and semigroup properties etc.?

There are many books about the $L^p$-theory of elliptic and parabolic equations covering, in particular the case of the Neumann Laplacian. See, for example,