Báo cáo toán học: "The t-stability number of a random graph" pptx

... edges of G intersected by the (dual) edges of C ∗ . Then G − F is actually a plane embedding, and we easily add the edges of F back to G − F , making a plane drawing D with at most  |F | 2  pairwise ... shortest paths in planar graphs. In: SODA 2005, Pro- ceedings, SIAM (2005), 146–155. [10] B. Mohar, A linear time algorithm for embedding graphs in an arbitrary surface. SIAM J....

Ngày tải lên: 07/08/2014, 15:23

... results of this paper are designed to deal with the case when the average degree of the graph is large. We shall prove that an r-regular graph without 3 and 5 cycles has an independence number of at ... instead of the average degree of the graph we have to use another measure of the concentration of edges. 8 References [1] Ajtai, M.,Koml ´ os, J. and Szemer ´ edi, E., A note...

Ngày tải lên: 07/08/2014, 06:20

... ≥ √ n ¯ d2 as claimed. This improves Denley’s Theorems 1 and 2. It is sharp for the regular complete bipartite graphs K aa . The above results are readily extended to graphs of larger odd girth. Lemma ... to n.LetA (respectively B) be the set of vertices v of G such that the minimum label on vertices at distance k or less from v is at even (respectively odd) distance k − 1orless. It is...

Ngày tải lên: 07/08/2014, 06:20

... Knopfmacher Department of Computational and Applied Mathematics University of Witwatersrand Johannesburg, South Africa e-mail: arnoldk@gauss.cam.wits.ac.za A. M. Odlyzko AT&T Labs - Research Florham Park, ... Combinatorics and Optimization University of Waterloo Waterloo, Ontario N2L 3G1, Canada e-mail: lbrichmo@watdragon.uwaterloo.ca D. Stark 2 Department of Mathematics and Stat...

Ngày tải lên: 07/08/2014, 06:20

... extremal permutations with 0 and n − 1 adjacent are as described in Theorem 4, and all such permutations are extremal. Proof Without loss of generality, suppose a permutation with 0 and n − 1 adjacent ... is easy to see that Theorem 4 is a correct characterisation of extremal sequences with that property. Lemma 5 Suppose n>2 and that some extremal permutation has 0 and n − 1 adjace...

Ngày tải lên: 07/08/2014, 07:21

... rows and columns of the adjacency matrix of G it is a block diagonal matrix in which every block is an all-1 square matrix, and as our graph G has no loops, this means that it is a union of complete ... a square all-1 matrix. Proof of Theorem 1.1: The square of the number of perfect matchings of G counts ordered pairs of such matchings. We claim that this is the numbe...

Ngày tải lên: 07/08/2014, 15:22

... journal of combinatorics 15 (2008), #R126 10 The Ramsey number of diamond-matchings and loose cycles in hypergraphs Andr´as Gy´arf´as ∗ Computer and Automation Research Institute Hungarian Academy ... copies graphs, Transactions of the American Mathematical Society 209 (1975), pp. 87-99. [5] F. Chung, Regularity lemmas for hypergraphs and quasi-randomness, Random Struc- tures and Al...

Ngày tải lên: 07/08/2014, 21:20

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Ngày tải lên: 05/08/2014, 10:20

... itself a right translation of S if (ab)ρ = a( bρ) for all a, b ∈ S. A left translation λ and a right translation ρ of S are said to be linked if a( λb)= (a )b for all a, b ∈ S. In this case, we call ... investigated the translational hull of a type -A semigroup, in particular, the result obtained by Ault [1] was sub- stantially generalized and extended. Thus, the translatio...

Ngày tải lên: 06/08/2014, 05:20

... we know that the most typical examples of basic Hopf algebras of finite representation type are Taft algebras and the dual of A( n, d, μ, q), which as an associative algebra is generated by two ... algebra is a kind of generalization of gener- alized Taft algebra and of course Taft algebra. Therefore, it is natural to ask the following question: whether is the quantum double of...

Ngày tải lên: 06/08/2014, 05:20