Laplacian matrix

Etymology
Named after (1749 – 1827), a French scholar whose work was important to the development of mathematics, statistics, physics and astronomy.

Noun

 * 1)  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 &minus;1 or 0 depending on whether there is or there is not (respectively) an edge connecting the pair of corresponding vertices.