Laplacian Matrix Definition

noun

A square n \times n matrix which describes an undirected graph of n vertices by letting rows and columns correspond to vertices, letting its diagonal elements contain the degrees of corresponding vertices and letting its non-diagonal elements contain either −1 or 0 depending on whether there is or there is not (respectively) an edge connecting the pair of corresponding vertices.

Wiktionary

Origin of Laplacian Matrix

Named after Pierre-Simon, marquis de Laplace (1749 - 1827), a French scholar whose work was important to the development of mathematics, statistics, physics and astronomy.

From Wiktionary