Krushkal polynomial of graphs on surfaces
نویسنده
چکیده
The Krushkal polynomial is the most general polynomial invariant of graphs on surfaces. It was introduced in [1]. A collection of edges forms a spanning quasi-tree if the regular neighborhood of the corresponding spanning subgraph has one boundary component. In the case of plane graphs it is just a spanning tree. The set of edges of a spanning quasi-trees is a feasible set of the corresponding delta-matroid. If the edges of the graph are ordered then one can introduces activities relative to a spanning quasi-tree [2]. The goal of my talk is to present a quasi-tree expansion of the Krushkal polynomial discovered by Clark Butler in [3].
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