Types of embedded graphs and their Tutte polynomials

TL;DR

This paper systematically extends the Tutte polynomial to various classes of embedded graphs, relating them to existing polynomials and providing new formulations and properties for each class.

Contribution

It introduces a unified approach to defining Tutte polynomials for four classes of embedded graphs and connects them to known graph polynomials.

Findings

Identifies a universal deletion-contraction invariant for each class

Provides state-sum formulations and duality relations

Relates new polynomials to Bollobás–Riordan, Krushkal, and Las Vergnas polynomials

Abstract

We take an elementary and systematic approach to the problem of extending the Tutte polynomial to the setting of embedded graphs. Four notions of embedded graphs arise naturally when considering deletion and contraction operations on graphs on surfaces. We give a description of each class in terms of coloured ribbon graphs. We then identify a universal deletion-contraction invariant (i.e., a `Tutte polynomial') for each class. We relate these to graph polynomials in the literature, including the Bollob\'as--Riordan, Krushkal, and Las Vergnas polynomials, and give state-sum formulations, duality relations, deleton-contraction relations, and quasi-tree expansions for each of them.