Báo cáo toán học: "Optimal Betti numbers of forest ideals" ppt

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Ngày tải lên: 05/08/2014, 15:20

Ngày tải lên: 05/08/2014, 15:21

Ngày tải lên: 05/08/2014, 15:21

... 61–72 Irreducible Quadratic Perturbation of Spatial Oscillator O. RabieiMotlagh 1 and Z. Afsharnejad 2 1 Dept. of Math., University of Birjand, Birjand, Iran 2 Dept. of Math., Ferdowsi University of Mashhad, ... guaranteeing existence (lack) of peri- odic solutions. We will see that iterative derivatives of the Poincare map play Irreducible Quadratic Perturbation...

Ngày tải lên: 06/08/2014, 05:20

... Handbook of Mathematical Functions,NationalBureauof Standards, Washington DC, 1972. 2. P. Erd˝os and P. Tur´an, On some problems of a statistical group theory, III,, Acta Math. Acad. Sci. Hungar. ... greater than √ n sincewemayalwaystakep = q) we may halve the distance from m to n by one application of this inequality. After at most log 2 n applications of the above inequality we ob...

Ngày tải lên: 07/08/2014, 06:22

... monotone subsequences of length 3 in L, R are also such subsequences of S.There are no monotone subsequences of S containing both 0 and n − 1. There are no monotone subsequences of S of the form a, ... up of k monotone descending subsequences, each of length n/k or n/k; clearly it has no monotone ascending subsequences of length k +1, and any monotone descendin...

Ngày tải lên: 07/08/2014, 07:21

... ,k (9) Let B be the matrix of the coefficients of the (k +1)n + k equations (7)-(9). Lemma 11 Matrix B is of full row rank. Proof. We extend the first part of the proof of Lemma 6 to the case k>2. Each ... the matrix of the coefficients of the 4n + 1 equations (1)-(6). Lemma 6 Matrix A is of full row rank. Proof.Eacharc(j, n +1),j =0, ,n, of each of the two colours interfere...

Ngày tải lên: 07/08/2014, 08:22

... proof of Theorem 1, and discussed three different zeta functions of any graph. Various proofs of Bass’ theorem were known. Kotani and Sunada [15] proved Bass’ theorem by using the property of ... Ihara zeta function of a fractal graph, and gave a determinant expression of it. We define the Bartholdi zeta function of a fractal graph, and present its determinant expressi...

Ngày tải lên: 07/08/2014, 21:21

... 4599. [3] H. Charalambous, Betti numbers of multigraded modules, J. Algebra, 137 (1991), 491-500. the electronic journal of combinatorics 16 (2009), #R36 11 3 Betti numbers of forest ideals Our first ... Griffith, Binomial behavior of Betti numbers for modules of finite length, Pacific J. Math, 133 (1988), 267-276. [9] M. Goff, Bounding Betti numbers of bipartite grap...

Ngày tải lên: 07/08/2014, 21:21

... maximized when G = K n . Some improvements of (1) for 1/ ( n − 2) < λ < 3, λ = 1 are given in Sections 4 and 5. 3 Maximal flat antichains of minimum si ze In this section we show that the ... inequality implies  x∈V d(x) 2 ≥ 4|E| 2 n , the electronic journal of combinatorics 16 (2009), #R69 17 Maximal at antichains of minimum weight Martin Grăuttmăuller Hochschule...

Ngày tải lên: 07/08/2014, 21:21

... distinguishing chromatic number of K n,n − M We denote by K n,n − M the graph obtained from the complete bipartite graph K n,n by deleting the edges of a perfect matching. This graph arises in the proof of ... c(b k−1 ) = ∆. Let S ⊆ V (G) consist of the union of all the vertices in levels 0 through k − 1 of T . Because of our choice of C and r, G[S] ∼ = T [S], with a ll le...

Ngày tải lên: 07/08/2014, 21:21

... graphs with maximum Laplacian spread among all tricyclic gr aphs of order n ≥ 11. Moreover, fo r 5 ≤ n ≤ 10, if G is one with maximum Laplacian spread of all tricyclic gra phs of order n, then G ... vertices of the star, respectively [4]. A tricyclic graph is a connected graph in which the number of edges equals the number of vertices plus two. In this paper, we stud...

Ngày tải lên: 07/08/2014, 21:21

... notion of universal cycles. In particular, we show that these cycles exist for certain classes of labeled graphs. In order to define a universal cycle of graphs, we must first extend the notion of ... Classification: 05C30 Abstract A universal cycle is a compact listing of a class of combinatorial objects. In this paper, we prove the existence of universal cycles of...

Ngày tải lên: 08/08/2014, 11:20

... l property of trees which was observed by Bruns and Hibi [2]. the electronic journal of combinatorics 17 (2010), #R9 6 A combinatorial proof of a formula for Betti numbers of a stacked polytope Suyoung ... Choi ∗ Department of Mathematical Sciences KAIST, Republic of Korea choisy@kaist.ac.kr (Current) Department of Mathematics Osaka City University, Japan ch...

Ngày tải lên: 08/08/2014, 11:20

... function, and the former is sharp in the sense that n log n is the true order of magnitude of the size of the largest dissociated subset of the set {0, 1} n . At the same time, the bound of Theorem ... every element of M, is a linear combination of the elements of Λ with the coefficients in {−1, 0, 1}. Hence, every subset sum of M is a linear combinatio...

Ngày tải lên: 08/08/2014, 14:23