Báo cáo toán học: "The 11-element case of Frankl’s conjecture" pptx

Ngày tải lên: 05/08/2014, 09:46

Ngày tải lên: 05/08/2014, 10:20

Ngày tải lên: 05/08/2014, 10:20

Ngày tải lên: 05/08/2014, 10:20

... set P (S) of all right translations) of the semigroup S forms a semigroup under the composition of mappings. By the translational hull of S, we mean a subsemigroup Ω(S) consisting of all bitranslations ... Journal of Mathematics 34:4 (2006) 441–447 The Translational Hull of a Strongly Right or Left Adequate Semigroup X. M. Ren 1 * and K. P. Shum 2 + 1 Dept. of Mathematics, Xi’...

Ngày tải lên: 06/08/2014, 05:20

... general- ization of [7], of (A(n, d, μ, q)) ∗cop . Our main result is to give the structure of projective modules of D(Γ n,d ). By this, we give the Ext-quiver (with relations) of D (Γ n,d )andshowthatD(Γ n,d ) ... > − −1, the elements X s K u,j and X s  F u,j are linearly independent. Proof. The proof of this lemma is same to the proof of Lemma 2.18 in [7]. For completeness...

Ngày tải lên: 06/08/2014, 05:20

... non–regular case we can still find bounds for the independence number in terms of the odd girth, but instead of the average degree of the graph we have to use another measure of the concentration of edges. 8 References [1] ... independence number of general graphs of a given odd girth. We shall prove some similar bounds to those we prove for regular graphs in terms of a measu...

Ngày tải lên: 07/08/2014, 06:20

... cycles. Let ¯ d be the average degree of vertices of G.Then α(G) ≥  n ¯ d/2. Proof. Since G contains no 3 or 5 cycles, we have α(G) ≥ d 1 (v) (consider the neighbors of v)andα(G) ≥ 1+d 2 (v) (consider ... 2 − ( k−1 k ) n k−1 k d 1 k . Proof. Immediate from Theorem 3. This improves Denley’s Theorem 4. References 1. Denley, T., The Independence number of graphs with large odd girth, Th...

Ngày tải lên: 07/08/2014, 06:20

... values of n, we shall use elementary estimates and some well-known bounds for ordinary partitions (of a number) to express most values of b n in terms of the number of ordinary partitions of k ... the number of partitions of (the number) n,andQis its ordinary generating function. Also, define p(n, k) to be the number of partitions of n with largest part at most k. We will ha...

Ngày tải lên: 07/08/2014, 06:20

... elementary invariants of a graph. For example, the number of edges of a graph is determined from that of the subgraphs as |E(G)| =  i |E(G i )|  (n−2). The degree sequence of G, denoted by D G , ... isomorphism class of a graph on at least three vertices is uniquely determined by the isomorphism classes of its vertex-deleted subgraphs is the most general case of problems...

Ngày tải lên: 07/08/2014, 06:20