论文标题

某些禁忌子图的​​非负特性图的分解

Decompositions of graphs of nonnegative characteristic with some forbidden subgraphs

论文作者

Niu, Lin, Li, Xiangwen

论文摘要

图$ g $的a {\ em $(d,h)$ - 分解}是订单对$(d,h)$,因此$ h $是$ g $的子图,其中$ h $最大的$ h $和$ d $是$ g-e(h)$ g-e(h)$ d $的最高度。如果$ g $具有$(d,h)$ - 分解,则图$ g $是{\ em $(d,h)$ - emposable}。令$ g $为非负特性表面中的图形。在本文中,我们证明了以下结果。 (1)如果$ g $没有和弦$ 5 $ - 或和弦$ 6 $ -Cycles或Conconcles $ 7 $ -CYCLE,则没有相邻的$ 4 $ -CYCLE,则$ G $是$(3,1)$ - 可分解的,这概括了Chen,Zhu and Zhu and Zhu and Wang [computs computs computs computs comput。数学。 Appl,56(2008)2073--2078]和张的结果[评论。数学。大学。 Carolin,54(3)(2013)339--344]。 (2)如果$ g $没有$ i $ -cycles或$ j $ -cycles对于任何子集$ \ {i,j \} \ subseteq \ {3,4,4,6 \} $是$(2,1)$ - 可分解的,这概括了Dong和dong和XU [dong and XU]的结果。 alg。 and Appl。,1(2)(2009),291--297]。

A {\em $(d,h)$-decomposition} of a graph $G$ is an order pair $(D,H)$ such that $H$ is a subgraph of $G$ where $H$ has the maximum degree at most $h$ and $D$ is an acyclic orientation of $G-E(H)$ of maximum out-degree at most $d$. A graph $G$ is {\em $(d, h)$-decomposable} if $G$ has a $(d,h)$-decomposition. Let $G$ be a graph embeddable in a surface of nonnegative characteristic. In this paper, we prove the following results. (1) If $G$ has no chord $5$-cycles or no chord $6$-cycles or no chord $7$-cycles and no adjacent $4$-cycles, then $G$ is $(3,1)$-decomposable, which generalizes the results of Chen, Zhu and Wang [Comput. Math. Appl, 56 (2008) 2073--2078] and the results of Zhang [Comment. Math. Univ. Carolin, 54(3) (2013) 339--344]. (2) If $G$ has no $i$-cycles nor $j$-cycles for any subset $\{i,j\}\subseteq \{3,4,6\}$ is $(2,1)$-decomposable, which generalizes the results of Dong and Xu [Discrete Math. Alg. and Appl., 1(2) (2009), 291--297].

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