Báo cáo toán học: "Two remarks concerning the theorem of S. Axler, S.-Y. A. Chang and D. Sarason " docx

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Ngày tải lên: 05/08/2014, 09:46

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Ngày tải lên: 05/08/2014, 15:20

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Ngày tải lên: 05/08/2014, 15:20

... of Mathematics 33:3 (2005) 350–356 Some Remarks on Weak Amenability of Weighted Group Algebras A. Pourabbas and M. R. Yegan Faculty of Mathematics and Computer Science, Amirkabir University of ... functions but such that  1 (G, ω) is not weakly amenable. For non-abelian groups, Borwick [2] gives a very interesting classification of weak amenability of Beurling al...

Ngày tải lên: 06/08/2014, 05:20

... terminology of dimension 2 posets, an increasing subsequence is a chain and a decreasing subsequence is an anti-chain. Permutations which are the union of an increasing and a decreasing subsequence M.D. ... figure the vertical and horizontal lines have the obvious separation meaning; for example, if R and W are red and white points we would ha...

Ngày tải lên: 07/08/2014, 06:22

... determined in all these cases. The final theorem gives at least a lower bound on P L q (u). According to Theorem 5, it is sufficent to consider only odd values of q. The following convention is used. ... some applications, let u(d) ≥ u ∈ N \{1}. (i) Let u = 3. Inequality (2) and Theorem 2 imply the condition 3d ≤ qn.Theorem5 shows that inequality (1) cannot improve this condition. (ii) L...

Ngày tải lên: 07/08/2014, 07:21

... several counting problems on the square lattice L n . There the authors gave the following bounds for the asymp- totics of f(n), the number of forests of L n ,and (n), the number of acyclic orienta- tions ... y>0andz t y =1. the electronic journal of combinatorics 10 (2003), #R4 15 Improved bounds for the number of forests and acyclic...

Ngày tải lên: 07/08/2014, 07:21

... particular, it contains exactly one occurrence of the greatest letter it contains, since between two the electronic journal of combinatorics 11 (2004), #R17 3 Improved bounds on the length of maximal abelian square-free ... m. Further, if there is a pair of (k − 1)’s in w m , one must be on the left half of s m and hence before the m in h m+1 ,and the othe...

Ngày tải lên: 07/08/2014, 08:20

... in the next section, to prove that a MNT graph of order n ≥ 10 has at least 3n−2 2 edges. The first one concerns the lower bound for the number of edges of MNH graphs. It is the combination of ... is not complete, then some internal vertex of Q has a neighbour in G − V (Q). the electronic journal of combinatorics 12 (2005), #R32 2 Lower Bound for the Size...

Ngày tải lên: 07/08/2014, 13:21

... key ingredient of our proof. Given the informal discussion above, the proof of Theorem 1.1 looks very roughly as follows. At the first part of the proof we consider the graph G(n, ρ) for a relatively ... claim holds for d − 1. We prove the claim for d. Let S = (G 1 , G 2 , . . . , G d ) be the sequence of the labels of the nodes u i , i ∈ [d], along the path...

Ngày tải lên: 07/08/2014, 21:21

... be the permutation corresponding to the transposed of B. We start with A 0,0 . Let A x,z be the matrix we have after k − 1 steps. Let the first row of A x,z be row number r and the first column of ... first column of A x,z be column number s of the original A 0,0 . Let the number of erased columns j such that j < p r be t k and the number the electronic...

Ngày tải lên: 08/08/2014, 01:20

... constraint in the structure of trees or indeed all higher plants. If we seek meaning in the list as a whole there remains the task of “seeing the wood for the trees”, selecting and arranging them into ... contain them. On the other hand, each could be examined for indications of non-viability. 4.2 Gradients But the intended purpose of the rules was to aid the...

Ngày tải lên: 08/08/2014, 14:22

... a non- empty Dyck prefix a nd k (resp. t) is the number of all consecutive falls in the end of τ (resp. p). Proof. Using the bijection of Fig. 6, under the inequality restrictions of relations ... evaluate the associated generating functions. Finally, in Section 6, we unify the main results of Sections 3, 4 and 5. We note that some of the results of t his...

Ngày tải lên: 08/08/2014, 14:23

... elementary symmetric function (with e 0 = 1 and e r = 0 for r < 0) and ′ denotes the conjugate partition. 2 Diagonal strips We begin with some connections between generating functions and determinants. Lemma ... Weierstrass product for the function sin(πz)/πz takes the form sin(πz) πz =  k≥1  1 − z 2 k 2  . (3.1) Consider the Taylor series expansion at z = 0. On the one hand, the coeffi...

Ngày tải lên: 08/08/2014, 14:23