Laplacian matrix of a graph

Another important symmetric matrix associated with a graph is the Laplacian matrix. This is the matrix L = A^TA, with A the arc-node incidence matrix, is another important symmetric matrix associated with the graph. It can be shown that the (i,)j element of the Laplacian matrix is given by
 L_{ij} = left{ right.


 begin{array}{ll} 1 & XXX  0 & 1 end{array}

See also: