On Tutte polynomials and cycles of plane graphs
Let t(G,x,y) be the Tutte polynomial (or dichromate) of the connected plane graph G. It is known (Martin; Las Vergnas) that t(G,x,x) can be expressed in terms of the family of partitions of the edge-set of the medial graph M(G) of G into non-crossing cycles. Moreover, t(G,-1,-1) can be expressed in terms of the number of crossing cycles of M(G) (Martin; Rosenstiehl and Read). Another result of Penrose on the number of edge-3-colorings of a cubic connected plane graph G can be viewed as an evaluation of t(G,0,-3) in terms of the family of partitions of the edge-set of M(G) into cycles avoiding certain transitions. We unify and generalize these results by giving expressions of t(G,x,y) in terms of cycle partitions of M(G) for all x, y such that (x-1)(y-1)\(\neq 0\) or \(x=y=1\).
scientific article; zbMATH DE number 3957141
scientific article