An element e of a 3-connected matroid M is essential if neither the deletion M\e nor the contraction M/e is 3-connected. Tutte's Wheels and Whirls Theorem proves that the only 3-connected matroids in which every element is essential are the wheels and whirls. In this paper, we consider those 3-conne
Matroidal families of finite connected nonhomeomorphic graphs exist
โ Scribed by Thomas Andreae
- Publisher
- John Wiley and Sons
- Year
- 1978
- Tongue
- English
- Weight
- 197 KB
- Volume
- 2
- Category
- Article
- ISSN
- 0364-9024
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โฆ Synopsis
Abstract
A matroidal family is a nonempty set โฑ of connected finite graphs such that for every arbitrary finite graph G the edge sets of the subgraphs of G which are isomorphic to an element of โฑ form a matroid on the edge set of G. In the present paper the question whether there are any matroidal families besides the four previously described by SimรตesโPereira is answered affirmatively. It is shown that for every natural number n โฉพ 2 there is a matroidal family that contains the complete graph with n vertices. For n = 4 this settles SimรตesโPereira's conjecture that there is a matroidal family containing all wheels.
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