Local connectivity and cycle xtension in claw-free graphs
نویسندگان
چکیده
Let G be a connected claw-free graph, M (G) the set of all vertices of G that have a connected neighborhood, and hM (G)i the induced subgraph of G on M (G). We prove that (i) if M (G) dominates G and hM (G)i is connected, then G is vertex pan-cyclic orderable, (ii) if M (G) dominates G; hM (G)i is connected, and G n M (G) is triangle-free, then G is fully 2-chord extendable, (iii) if M (G) dominates G and the number of components of hM (G)i does not exceed the connectivity of G, then G is hamiltonian.
منابع مشابه
On the edge-connectivity of C_4-free graphs
Let $G$ be a connected graph of order $n$ and minimum degree $delta(G)$.The edge-connectivity $lambda(G)$ of $G$ is the minimum numberof edges whose removal renders $G$ disconnected. It is well-known that$lambda(G) leq delta(G)$,and if $lambda(G)=delta(G)$, then$G$ is said to be maximally edge-connected. A classical resultby Chartrand gives the sufficient condition $delta(G) geq frac{n-1}{2}$fo...
متن کاملOn cycle lengths in claw-free graphs with complete closure
We show a construction that gives an infinite family of claw-free graphs of connectivity κ = 2, 3, 4, 5 with complete closure and without a cycle of a given fixed length. This construction disproves a conjecture by the first author, A. Saito and R.H. Schelp.
متن کاملForbidden graphs and group connectivity
Many researchers have devoted themselves to the study of nowhere-zero flows and group connectivity. Recently, Thomassen confirmed the weak 3-flow conjecture, which was further improved by Lovász, Thomassen, Wu and Zhang who proved that every 6-edge-connected graph is Z3-connected. However, Conjectures 1 and 2 are still open. Conjecture 2 implies Conjecture 1 by a result of Kochol that reduces C...
متن کاملt-Perfection Is Always Strong for Claw-Free Graphs
A connected graph G is called t-perfect if its stable set polytope is determined by the non-negativity, edge and odd-cycle inequalities. Moreover, G is called strongly t-perfect if this system is totally dual integral. It is an open problem whether t-perfection is equivalent to strong t-perfection. We prove the equivalence for the class of claw-free graphs.
متن کاملClaw-free graphs - A survey
In this paper we summarize known results on claw-free graphs. The paper is subdivided into the following chapters and sections: 1. Introduction 2. Paths, cycles, hamiltonicity a) Preliminaries b) Degree and neighborhood conditions c) Local connectivity conditions d) Further forbidden subgraphs e) Invariants f) Squares g) Regular graphs h) Other hamiltonicity related results and generalizations ...
متن کاملذخیره 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 ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Ars Comb.
دوره 47 شماره
صفحات -
تاریخ انتشار 1997