Product distance matrix of a tree with matrix weights
نویسندگان
چکیده
Let T be a tree on n vertices and let the n− 1 edges e1, e2, . . . , en−1 have weights that are s× s matrices W1,W2, . . . ,Wn−1, respectively. For two vertices i, j, let the unique ordered path between i and j be pi,j = er1er2 . . . erk . Define the distance between i and j as the s × s matrix Ei,j = ∏k p=1Wep . Consider the ns × ns matrix D whose i, j-th block is the matrix Ei,j . We give a formula for det(D) and for its inverse, when it exists. These generalize known results for the product distance matrix when the weights are real numbers.
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