Apex graphs with embeddings of face-width three
نویسنده
چکیده
Aa apex graph is a graph which has a vertex whose removal makes the resulting graph planar. Embeddings of apex graphs having face-width three are characterized. Surprisingly, there are such embeddings of arbitrarily large genus. This solves a problem of Robertson and Vitray. We also give an elementary proof of a result of Robertson, Seymour, and Thomas 5] that any embedding of an apex graph in a nonorientable surface has face-width at most two.
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ورودعنوان ژورنال:
- Discrete Mathematics
دوره 176 شماره
صفحات -
تاریخ انتشار 1997