Dual complementary polynomials of graphs and combinatorial interpretation on the values of the Tutte polynomial at positive integers
Abstract
We introduce a modular (integral) complementary polynomial () of two variables of a graph by counting the number of modular (integral) complementary tension-flows (CTF) of with an orientation . We study these polynomials by further introducing a cut-Eulerian equivalence relation on orientations and geometric structures such as the complementary open lattice polyhedron , the complementary open 0-1 polytope , and the complementary open lattice polytopes with respect to orientations . The polynomial () is a common generalization of the modular (integral) tension polynomial () and the modular (integral) flow polynomial (), and can be decomposed into a sum of product Ehrhart polynomials of complementary open 0-1 polytopes . There are dual complementary polynomials and , dual to and respectively, in the sense that the lattice-point counting to the Ehrhart polynomials is taken inside a topological sum of the dilated closed polytopes . It turns out that the polynomial is Whitney's rank generating polynomial , which gives rise to a combinatorial interpretation on the values of the Tutte polynomial at positive integers. In particular, some special values of and ( and ) count the number of certain special kinds (of equivalence classes) of orientations.
Keywords
Cite
@article{arxiv.1105.2675,
title = {Dual complementary polynomials of graphs and combinatorial interpretation on the values of the Tutte polynomial at positive integers},
author = {Beifang Chen},
journal= {arXiv preprint arXiv:1105.2675},
year = {2013}
}
Comments
28 pages, 3 figures