Vertex decomposability and regularity of very well-covered graphs

被引:47
|
作者
Mahmoudi, Mohammad [1 ]
Mousivand, Amir [1 ]
Crupi, Marilena [2 ]
Rinaldo, Giancarlo [2 ]
Terai, Naoki [3 ]
Yassemi, Siamak [4 ]
机构
[1] Islamic Azad Univ IAU, Dept Math, Sci & Res Branch, Tehran, Iran
[2] Univ Messina, Dipartimento Matemat, I-98166 Messina, Italy
[3] Saga Univ, Dept Math, Fac Culture & Educ, Saga 8408502, Japan
[4] Univ Tehran, Coll Sci, Sch Math Stat & Comp Sci, Tehran, Iran
关键词
D O I
10.1016/j.jpaa.2011.02.005
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
A graph is called very well-covered if it is unmixed without isolated vertices such that the cardinality of each minimal vertex cover is half the number of vertices. We first prove that a very well-covered graph is Cohen-Macaulay if and only if it is vertex decomposable. Next, we show that the Castelnuovo-Mumford regularity of the quotient ring of the edge ideal of a very well-covered graph is equal to the maximum number of pairwise 3-disjoint edges. (C) 2011 Elsevier B.V. All rights reserved.
引用
收藏
页码:2473 / 2480
页数:8
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