We introduce the notion of the L-core of a graph what enables a simple description of some properties of the eigenspace of the eigenvalue — 2 in generalized line graphs and an elegant formulation of ...
Let $\Gamma\backslash\mathscr{H}$ be a finite volume symmetric space with H the product of half planes. Let Δi be the Laplacian on the ith half plane, and assume that we have a cusp form φ, so we have ...