Hodge Laplacians on Weighted Simplicial Complexes: Forms, Closures, and Essential Self-Adjointness

Abstract: We establish explicit operator norm bounds and essential self-adjointness criteria for discrete Hodge Laplacians on weighted graphs and simplicial complexes. For unweighted $d$-regular graphs we prove the universal estimate $|\widetilde{\Delta}_{1,*}|\le 4(d-1)$, and we provide weighted extensions with a sharp comparability constant. These bounds apply without geometric completeness or curvature assumptions and ensure essential self-adjointness on natural cores. The approach extends to higher degrees via dual up/down degrees, and we show a unitary equivalence between skew and symmetric models on colorable complexes. For periodic lattices we complement the universal bounds with exact Floquet--Bloch constants, typically of order $2d$, illustrating both the sharpness in growth and the generality of our method.