... class="bi x1 y1 w2 h 2" alt =""
Ngày tải lên: 05/08/2014, 09:46
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Ngày tải lên: 05/08/2014, 09:46
Báo cáo toán học: " An Eigenvalue Characterization of Antipodal Distance-Regular Graph" ppt
... E. R. van Dam and W. H. Haemers, Eigenvalues and the diameter of graphs, Linear and Multilinear Algebra 39 (1995), 33–44. [8] E. R. van Dam and W. H. Haemers, A characterization of distance-regular ... study two spectral characterizations of antipodal distance-regular graphs. The fist one establishes that the distance-regular graphs which are antipodal the electronic journal...
Ngày tải lên: 07/08/2014, 06:22
Báo cáo toán học: "On the number of perfect matchings and Hamilton cycles in -regular non-bipartite graphs" ppsx
... n)k −1 φ(k). In either case, the inequality in part 1 of the lemma holds. On the number of perfect matchings and Hamilton cycles in -regular non-bipartite graphs Alan Frieze ∗ Department of Mathematical ... of combinatorics 7 (2000), #R57 4 3 Hamilton Cycles A Hamilton cycle is the union of two perfect matchings and so h(G) ≤ 1 2 m(G) 2 a...
Ngày tải lên: 07/08/2014, 06:22
Báo cáo toán học: "On the orbits of Singer groups and their subgroups" pot
... orbits of Singer groups or subgroups of Singer groups. It seems, however, that only point (and, in the case the electronic journal of combinatorics 9 (2002), #R15 8 orbits of any Singer cycle of Σ n−1 on ... In the statement of the following theorem, à denotes the Măobius function, the basic properties of which can be found in, for example, [1]. Theore...
Ngày tải lên: 07/08/2014, 06:23
Báo cáo toán học: "Regular character tables of symmetric groups" docx
... determinant of the character tables of finite symmetric groups. It is a well-known fact that if X n is the character table of the symmetric group S n , then the absolute value of the determinant of X n equals ... as the product of all parts of all partitions of n. It also equals b n , which is defined as the product of all factorials of all multiplicities of part...
Ngày tải lên: 07/08/2014, 07:21
Báo cáo toán học: "Distinguishing numbers for graphs and groups" docx
... |Γ|≤m! and the subset {y 1 , ,y j } satisfies 1. φ(y i )=i for each i, 2. y i+1 is in Γ i−1 .y i for each i from 2 to j − 1, and y 1 is in Γ j−1 .y j , then j ≤ m and |Γ i−1 .y i |≥j − i + 2for each ... shows this and two other graphs with the same automorphism group and demonstrates that all three have different distinguishing numbers. This example disproves a conjecture in [...
Ngày tải lên: 07/08/2014, 08:20
Báo cáo toán học: "The Linear Complexity of a Graph" docx
... recoverable using any algorithm designed to compute the product of an adjacency matrix of the graph and an arbitrary vector. The linear complexity of a graph may therefore be seen as a measure of ... adjacency matrices of graphs, and a working knowledge of the linear complexity of a linear transformation. An excellent reference for linear complexity, and al...
Ngày tải lên: 07/08/2014, 13:21
Báo cáo toán học: "Weighted Zeta Functions of Graph Coverings" docx
... runs over all equivalence classes of prime, reduced cycles of G, and | C | is the length of C. Zeta functions of graphs started from zeta functions of regular graphs by Ihara [8]. In [8], he showed ... Sato [10] showed that the zeta function of a regular covering of G is a product of L -functions of G. Stark and Terras [16] treated zeta functions of bipartit...
Ngày tải lên: 07/08/2014, 13:21
Báo cáo toán học: "A short proof of a theorem of Kano and Yu on factors in regular graphs" pot
... and y. Then G is a 4 -regular graph, and G has a 1-factor con- taining e and a 1-factor avoiding e. According to Theorem 3, G has a k-factor containing e and a k-factor avoiding e for every k ... containing e and a 1-factor avoiding e, then G has a k-factor containing e and a k-factor avoiding e for every k ∈ {1, 2, . . . , r − 1}. Proof. Let F and F e be two...
Ngày tải lên: 07/08/2014, 13:21
Báo cáo toán học: "he spectral radius of subgraphs of regular graphs" ppt
... regular graph and e be an edge of G. If H is a component of G e with à (H) = à (G e) , then à (G) µ (H) > 1 Diam (H) |H| . This lemma follows easily from Theorem 2.1 of [2] and its proof ... its proof is omitted. Proofs Proof of Theorem 2 Write dist F (s, t) for the length of a shortest path joining two vertices s and t in a graph F. Write d for the degree of G, let H = G uv,...
Ngày tải lên: 07/08/2014, 13:21
Báo cáo toán học: "Regular spanning subgraphs of bipartite graphs of high minimum degree" docx
... referee for the useful remarks. the electronic journal of combinatorics 14 (2007), #N21 6 Regular spanning subgraphs of bipartite graphs of high minimum degree B´ela Csaba ∗† Submitted: Aug 1, 2007; ... electronic journal of combinatorics 14 (2007), #N21 2 3.2 Proof of part II For proving part II of the theorem we want to construct a class of balanced bipartite...
Ngày tải lên: 07/08/2014, 15:22
Báo cáo toán học: "On the Number of Matchings in Regular Graphs" pptx
... get the numerator of the right-hand side of (4.10). Divide this number of choices by the number of permutations of {1, . . . , rn} to deduce the lemma. ✷ Using the methods in the proof of Theorem ... := r i=1 A i . Let m ∈ min(p, q). Then perm m A is the number of m -matchings of G := ∨ r i=1 G i , which is equal to the number of m -matchings o...
Ngày tải lên: 07/08/2014, 21:20
Báo cáo toán học: "vs. Algebraic Characterizations of Completely Pseudo-Regular Codes" pps
... characterization of completely pseudo-regular codes in algebraic sense, which coincides with the one of Theorem 3.3. This proves the equivalence between combinatorial and algebraic approaches to completely pseudo-regular ... So, once proved, we speak indistinctly of one or another concept. Theorem 4.2 A se t of v ertices C ⊂ V of a graph Γ is a completely pseudo-regul...
Ngày tải lên: 08/08/2014, 12:22
Báo cáo toán học: "Regular factors of regular graphs from eigenvalues" pptx
... root of f 1 (x) = 0. This completes the proof. ✷ 3 The proof of The orems 1.5 and 1.6 We will need the following technical lemma whose proof is an easy modification of the proof of Theorem 2.2 from ... graph G of order v has a 1-factor when v is even, and a matching of order v − 1 when v is odd. In [11], the author studied the relation of eigenvalues and regular factors of...
Ngày tải lên: 08/08/2014, 12:23