【24h】

Excluding a large theta graph

机译:不包括一个大的θ图表

获取原文
获取原文并翻译 | 示例
           

摘要

A theta graph, denoted theta(a,b,c), is a graph of order a+b+c-1 consisting of a pair of vertices and three internally-disjoint paths between them of lengths a, b, and c. In this paper we study graphs that do not contain a large theta(a,b,c) minor. More specifically, we describe the structure of theta(1,2,t)-, theta(2,2,t)-, theta(1,t,t)-, theta(2,t,t)-, and theta(t,t,t)-free graphs where t is large. The main result is a characterization of theta(t,t,t)-free graphs for large t. The 3-connected theta(t,t,t)-free graphs are formed by 3-summing graphs without a long path to certain planar graphs. The 2-connected theta(t,t,t)-free graphs are then built up in a similar fashion by 2- and 3-sums. This result implies a well-known theorem of Robertson and Chakravarti on graphs that do not have a bond containing three specified edges. (C) 2018 Elsevier Inc. All rights reserved.
机译:Theta图表,表示(a,b,c),是由一对顶点和长度A,B和C之间的三个内部不相交的路径组成的订单A + B + C-1的曲线图。 在本文中,我们研究不包含大型θ(a,b,c)次要的图表。 更具体地,我们描述了θ的结构(1,2,T) - ,θ(2,2,t) - ,θ(1,t,t) - ,theta(2,t,t) - 和theta (t,t,t) - 免费图形的图表。 主要结果是θ(t,t,t)的表征 - 用于大的t.free图表。 通过3求图形成3连接的THETA(T,T,T)--FREE图,而没有长路径到某些平面图。 然后,通过2和3和,以类似的方式建立2连接的THETA(T,T,T)-FREE图形。 该结果暗示Robertson和Chakravarti在没有包含三个指定边缘的键的图表上的众所周知的定理。 (c)2018年Elsevier Inc.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号