{ "id": "math/0508178", "version": "v2", "published": "2005-08-10T11:15:17.000Z", "updated": "2006-02-04T12:30:45.000Z", "title": "Forest matrices around the Laplacian matrix", "authors": [ "Pavel Chebotarev", "Rafig Agaev" ], "comment": "19 pages, presented at the Edinburgh (2001) Conference on Algebraic Graph Theory", "journal": "Linear Algebra and Its Applications. 2002. V. 356. 253--274", "doi": "10.1016/S0024-3795(02)00388-9", "categories": [ "math.CO" ], "abstract": "We study the matrices Q_k of in-forests of a weighted digraph G and their connections with the Laplacian matrix L of G. The (i,j) entry of Q_k is the total weight of spanning converging forests (in-forests) with k arcs such that i belongs to a tree rooted at j. The forest matrices, Q_k, can be calculated recursively and expressed by polynomials in the Laplacian matrix; they provide representations for the generalized inverses, the powers, and some eigenvectors of L. The normalized in-forest matrices are row stochastic; the normalized matrix of maximum in-forests is the eigenprojection of the Laplacian matrix, which provides an immediate proof of the Markov chain tree theorem. A source of these results is the fact that matrices Q_k are the matrix coefficients in the polynomial expansion of adj(a*I+L). Thereby they are precisely Faddeev's matrices for -L. Keywords: Weighted digraph; Laplacian matrix; Spanning forest; Matrix-forest theorem; Leverrier-Faddeev method; Markov chain tree theorem; Eigenprojection; Generalized inverse; Singular M-matrix", "revisions": [ { "version": "v2", "updated": "2006-02-04T12:30:45.000Z" } ], "analyses": { "subjects": [ "05C50", "05C05", "05C20", "15A48", "15A09" ], "keywords": [ "laplacian matrix", "markov chain tree theorem", "generalized inverse", "weighted digraph", "polynomial" ], "tags": [ "conference paper", "journal article" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math......8178C" } } }