Báo cáo toán học: "The Borodin-Kostochka conjecture for graphs containing a doubly critical edge" pptx

... If p a contains more than one vertex (say p a = a, a 2 , a 3 , . . . , a n ), then (a, a 2 ) is lonely since p a is a path in L C (G). But {a} is a singleton color class, so (a 2 , a) is also lonely. ... 2007 Mathematics Subject Classification: 05C15 Abstract We prove that if G is a graph containing a doubly- critical edge and satisfying χ ≥ ∆ ≥ 6, then G contains...

Ngày tải lên: 07/08/2014, 15:22

... that u can have more than one private neighbor. Also note that for a vertex u of D G both conditions of Theorem 1 can hold at the same time, that is, it can have a private neighbor and be nonadjacent ... conjecture: For any graphs G and H, γ(G  H) ≥ γ(G)γ(H), where γ, as usual, denotes the domination number of a graph, and G  H is the Cartesian product of graphs G and H. It b...

Ngày tải lên: 07/08/2014, 08:22

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Ngày tải lên: 05/08/2014, 15:20

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Ngày tải lên: 05/08/2014, 15:20

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Ngày tải lên: 05/08/2014, 15:21

... Then we may assume that e w ¯ J may be written as a linear combination of column standard polytabloids by Lemma 3.1. Thus, because of Remark 3.4, we may always take w ¯ J to have standard columns. ... the standard bitableau t given in (1.2). Let  t denote the standard bitableau obtained from the t by interchanging rows and columns, as in a matrix. Now, take another standard ∆-tableau  ¯...

Ngày tải lên: 07/08/2014, 21:20

... and 2. As a result, we are able to prove the following two propositions which are im- portant for t he characterizations of graphs that have a bijective graceful N-labeling and graphs that have ... that infinite graphs built by certain types of graph amalgamations possess bijective edge-magic Z-labeling. An infinite graph makes constructing a magic labeling easier because both the...

Ngày tải lên: 07/08/2014, 21:21

... feedback. Thanks to Donald Keedwell for some historical remarks. Thanks also to Brendan McKay, Richard Brualdi, Xiaoguang Liu, Gang Wang and Arthur Yang for assistance tracking down references. The author ... ×n Latin rectangles as fixed parameter tractable. Wilf arrived at this definition aft er he refereed a paper proposing a “formula” for the answer to [what is L n ?], and realizin...

Ngày tải lên: 08/08/2014, 01:20

... modular metric space induced by w and T : X w → X w be an arbitrary mapping. A mapping T is called a contraction if for each x, y ∈ X w and for all λ > 0 there exists 0 ≤ k < 1 such that w λ (T ... this spaces, on the same idea he was defined the notion of a modular on an arbitrary set and develop the the- ory of metric spaces generated by modular such that called the modular m...

Ngày tải lên: 20/06/2014, 21:20

... results for graphs of odd girth at least 7. Dealing with graphs with larger odd girth will simply require a generalisation of this argument. Theorem 1 Let G be a graph of order n containing containing ... E., Ramsey numbers and an approximation algorithm for the vertex cover problem, Acta Informatica 22 (1985), 115–123. [7] Shearer, J.B., A note on the independence number of t...

Ngày tải lên: 07/08/2014, 06:20