A generalization of a result of Häggkvist and Nicoghossian

نویسندگان

  • Douglas Bauer
  • Hajo Broersma
  • Henk Jan Veldman
  • Li Rao
چکیده

We consider only finite undirected graphs without loops or multiple edges. Our terminology is standard except as indicated. A good reference for any undefined terms is [4]. We begin by introducing some definitions and convenient notation. The set of vertices of a graph G is denoted by V(G) or just V; the set of edges by E(G) or just E. We use K for the connectivity of a graph, and c1 to denote the cardinality of a maximum set of independent vertices in a graph. If C is a cycle in a graph G we call C a dominating cycle if every edge of G has at least one of its vertices on C. Given an (x, y)-path P of G we denote by P the path P with an orientation from x to y. If u, v E V(P), then UPU denotes the consecutive vertices on P from u to u in the direction specified by P. If u # y, then u+ denotes the

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A generalization of Villarreal's result for unmixed tripartite graphs

‎In this paper we give a characterization of unmixed tripartite‎ ‎graphs under certain conditions which is a generalization of a‎ ‎result of Villarreal on bipartite graphs‎. ‎For bipartite graphs two‎ ‎different characterizations were given by Ravindra and Villarreal‎. ‎We show that these two characterizations imply each other‎.

متن کامل

A Generalization of M-Small Modules

In this paper we introduce a generalization of M-small modules and discuss about the torsion theory cogenerated by this kind of modules in category . We will use the structure of the radical of a module in  and get some suitable results about this class of modules. Also the relation between injective hull in  and this kind of modules will be investigated in this article.   For a module  we show...

متن کامل

Kotzig frames and circuit double covers

A cubic graph H is called a Kotzig graph if H has a circuit double cover consisting of three Hamilton circuits. It was first proved by Goddyn that if a cubic graph G contains a spanning subgraph H which is a subdivision of a Kotzig graph then G has a circuit double cover. A spanning subgraph H of a cubic graph G is called a Kotzig frame if the contracted graph G/H is even and every non-circuit ...

متن کامل

On a generalization of the Evans Conjecture

The Evans Conjecture states that a partial Latin square of order n with at most n− 1 entries can be completed. In this paper we generalize the Evans Conjecture by showing that a partial r-multi Latin square of order nwith at most n−1 entries can be completed. Using this generalization, we confirm a case of a conjecture of Häggkvist. © 2007 Elsevier B.V. All rights reserved.

متن کامل

A new characterization for Meir-Keeler condensing operators and its applications

Darbo's fixed point theorem and its generalizations play a crucial role in the existence of solutions in integral equations. Meir-Keeler condensing operators is a generalization of Darbo's fixed point theorem and most of other generalizations are a special case of this result. In recent years, some authors applied these generalizations to solve several special integral equations and some of the...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • J. Comb. Theory, Ser. B

دوره 47  شماره 

صفحات  -

تاریخ انتشار 1989