Báo cáo toán học: "Parking functions, empirical processes, and the width of rooted labeled trees" pps
... motivations of Odlyzko and Wilf, when they study the width of labeled trees, is to give a tight estimate for the average bandwidth of this class of tree. 2 The breadth first search random walk From ... initially (0). Then, at each of the n following stages of the BFS, the vertex x at the head of the queue is removed from the queue, and all “new” neighbor...
Ngày tải lên: 07/08/2014, 06:22
... Λ(π i−1 ,π i )andminB . It is easy to see that Γ m is a tree. Root Γ m at the vertex 1 and erase the vertex labels. If v i is the vertex of e i farthest from the root, then move the label i of the edge ... ,Λ(π n−1 ,π n )). 3.1 Theorem. The labels Λ(m) of the maximal chains of NC n+1 consist of the parking functions of length n,eachoccuringonce. Proof. If Λ(π...
Ngày tải lên: 07/08/2014, 06:22
... have the same number of elements. First we remark that there is a natural action of S n on the set of parking functions, which permutes the a j . There is also an action of S n on the set of factorizations, ... w]. If W = S n is the group of permutations of [1,n], then the reflections are the transposi- tions, and w is the cycle (1 2 n). To any permutation σ ∈...
Ngày tải lên: 07/08/2014, 06:23
Báo cáo toán học: "Parking functions, stack-sortable permutations, and spaces of paths in the Johnson graph" docx
... arrive at the first element of p, p k . At this point, the top of the stack is the index of the last element of q encountered. We move the top of the stack out, as the first entry of the right ... arrive at the element p s of p, the top of the stack is the index of the smallest element of q which is not smaller than p s , other than the elements...
Ngày tải lên: 07/08/2014, 07:21
Báo cáo toán học: "COMPOSITION SUM IDENTITIES RELATED TO THE DISTRIBUTION OF COORDINATE VALUES IN A DISCRETE SIMPLEX" pptx
... pictures of weight k.Acard of weight k is a pair consisting of a picture of weight k and a k-element subset of N that we will call the label set of the card. A hand of weight n and size l is a set of ... bijection between the set of compositions of n −2by{1, 2} and the set of compositions of n − 1 by odd numbers. The bijection works by prepending a 1 to...
Ngày tải lên: 07/08/2014, 06:20
Báo cáo toán học: "Weakly Self-Avoiding Words and a Construction of Friedman" ppt
... self-avoiding then we append q0andq1 to the end of the queue. the electronic journal of combinatorics 8 (2001), #N2 2 Weakly Self-Avoiding Words and a Construction of Friedman Jeffrey Shallit ∗ and Ming-wei ... subword of “introduction”. 1 We use the notation x[k]todenotethek’th letter chosen from the string x. We write x[a b] to denote the subword of x of length b...
Ngày tải lên: 07/08/2014, 06:22
Báo cáo toán học: "Weighted Aztec Diamond Graphs and the Weyl Character Formula" doc
... Given a matching m of the Aztec diamond graph A, define the weight of the matching (m) to be the product of the weights of all the edges in the matching. Then the weight of the Aztec graph A is (A)= m (m), ... graph of order n is the dual graph to the Aztec diamond of order n in which the vertices are the squares and an edge joins two vertices if...
Ngày tải lên: 07/08/2014, 08:20
Báo cáo toán học: " h∗-vectors, Eulerian polynomials and stable polytopes of graph" pdf
... faces of ∆ for 0 ≤ i ≤ d − 1andf −1 =1. We say that ∆ is a triangulation of a polytopal complex F if the union of the faces of ∆ is equal to the union of the faces of F and every face of ∆ is ... from the description of the facets of P that if I 0 ⊂ I 1 ⊂···⊂I e is a chain of nonempty ideals of Ω 0 as in the definition of the ideal height for Ω then t...
Ngày tải lên: 07/08/2014, 08:22
Báo cáo toán học: "A note on polynomials and f -factors of graphs" docx
... |E|. Theorem 1 can also be extended to hypergraphs, but the appropriate condition on |f(v)| then depends on the upper rank of the hypergraph – that is, the size of the largest hyperedge. The proofs ... 1}, then F is the edge set of a non-trivial partial f-factor of G. 3 Concluding Remarks We mention a possible direction for extending the results of Theorem 1 and Th...
Ngày tải lên: 07/08/2014, 15:22
Báo cáo toán học: "Chromatic Graphs, Ramsey Numbers and the Flexible Atom Conjecture" potx
... some c ∈ R and realize the above as a quadratic polynomial in c. Since the coefficient of c 2 is negative, the function is concave down. By finding the zeros of this polynomial in terms of n and then ... B m+ for m ≤ . Then by making superficial changes to the remainder of the proof we establish the result for the nonsymmetric case. Thus we have the following: the...
Ngày tải lên: 07/08/2014, 15:23