In this paper, it is shown that, for a minor-closed class ~ of matroids, the class of matroids in which every hyperplane is in Jยข' is itself minor-closed and has, as its excluded minors, the matroids U1,1 @ N such that N is an excluded minor for ,g. This result is applied to the class of matroids of
Connected Hyperplanes in Binary Matroids
โ Scribed by Jennifer McNulty; Haidong Wu
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 125 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0095-8956
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โฆ Synopsis
In this paper, we prove that any simple and cosimple connected binary matroid has at least four connected hyperplanes. We further prove that each element in such a matroid is contained in at least two connected hyperplanes. Our main result generalizes a matroid result of Kelmans, and independently, of Seymour. The following consequence of the main result generalizes a graph result of Thomassen and Toft on induced non-separating cycles and another graph result of Kaugars on deletable vertices. If G is a simple 2-connected graph with minimum degree at least 3, then, for every edge e, there are at least two induced non-separating cycles avoiding e and two deletable vertices non-incident to e. Moreover, G has at least four induced non-separating cycles.
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