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101.
Let V be a vertex operator algebra and m, n ≥ 0. We construct an A
n
(V)-A
m
(V)-bimodule A
n,m
(V) which determines the action of V from the level m subspace to level n subspace of an admissible V-module. We show how to use A
n,m
(V) to construct naturally admissible V-modules from A
m
(V)-modules. We also determine the structure of A
n,m
(V) when V is rational.
Chongying Dong was supported by NSF grants, China NSF grant 10328102 and a Faculty research grant from the University of California
at Santa Cruz. Cuipo Jiang was supported in part by China NSF grant 10571119. 相似文献
102.
采用批式离子交换法研究了磷酸可待因在安伯来特IRP-69上的离子交换平衡特性、动力学及热力学特征.结果表明,在3个温度(298K、308K和318K)及研究的浓度范围内,离子交换吸附等温方程和Freundlich方程都能够对磷酸可待因在安伯来特IRP-69上的离子交换平衡等温线进行很好的拟合,其离子交换动力学特征基本符合二级动力学方程.磷酸可待因在安伯来特IRP-69上的离子交换行为的热力学参数(ΔH、ΔG、ΔS)都小于0.在3个温度(298K、308K和318K)下,同一初始浓度(350mmol/L)的磷酸可待因在安伯来特IRP-69上的平衡交换吸附量分别为1.1295mmol/g、1.1203 mmol/g和1.1129 mmol/g. 相似文献
103.
The purpose of this paper is to develop compact expressions for the Fisher information matrix (FIM) of a Gaussian stationary vector autoregressive and moving average process with exogenous or input variables, a vector ARMAX or VARMAX process. We develop a representation of the FIM based on multiple Sylvester matrices. An extension of this representation yields another one but in terms of tensor Sylvester matrices. In order to obtain the results presented in this paper, the approach used in [A. Klein, G. Mélard, P. Spreij, On the resultant property of the Fisher information matrix of a vector ARMA process, Linear Algebra Appl. 403 (2005) 291-313] is extended. 相似文献
104.
Dieter Rautenbach 《Discrete Mathematics》2008,308(11):2325-2329
Let G be a graph of order n, minimum degree δ?2, girth g?5 and domination number γ. In 1990 Brigham and Dutton [Bounds on the domination number of a graph, Q. J. Math., Oxf. II. Ser. 41 (1990) 269-275] proved that γ?⌈n/2-g/6⌉. This result was recently improved by Volkmann [Upper bounds on the domination number of a graph in terms of diameter and girth, J. Combin. Math. Combin. Comput. 52 (2005) 131-141; An upper bound for the domination number of a graph in terms of order and girth, J. Combin. Math. Combin. Comput. 54 (2005) 195-212] who for i∈{1,2} determined a finite set of graphs Gi such that γ?⌈n/2-g/6-(3i+3)/6⌉ unless G is a cycle or G∈Gi.Our main result is that for every i∈N there is a finite set of graphs Gi such that γ?n/2-g/6-i unless G is a cycle or G∈Gi. Furthermore, we conjecture another improvement of Brigham and Dutton's bound and prove a weakened version of this conjecture. 相似文献
105.
We study irreducible representations for the Lie algebra of vector fields on a 2-dimensional torus constructed using the generalized Verma modules. We show that for a certain choice of parameters these representations remain irreducible when restricted to a loop subalgebra in the Lie algebra of vector fields. We prove this result by studying vertex algebras associated with the Lie algebra of vector fields on a torus and solving non-commutative differential equations that we derive using the vertex algebra technique. 相似文献
106.
In this paper, we characterize (i) linear transformations from one space of Boolean matrices to another that send pairs of distinct rank one elements to pairs of distinct rank one elements and (ii) surjective mappings from one space of Boolean matrices to another that send rank one matrices to rank one matrices and preserve order relation in both directions. Both results are proved in a more general setting of tensor products of two Boolean vector spaces of arbitrary dimension. 相似文献
107.
《Journal of Macromolecular Science: Physics》2013,52(6):1265-1280
Abstract The broadband dielectric spectroscopy (10?3–106 Hz) is used to study the effect of stress-strain cycles on the dielectric properties of butyl rubber vulcanizates filled with silica. The influence of chemical modification of the surface of the silica by silane coupling agent (Si69) also was investigated. In addition Transmission Electron Microscopy (TEM) and Differential Scanning Calorimetry (DSC) were carried out. Dielectric investigations of the samples were done after stress-strain cycles with maximum elongation 26%, 40%, 60%, and 80% from elongation at break, respectively. It was found that the dielectric properties recovered after storage at room temperature for about one year. 相似文献
108.
B.V. Subramanya Bharadwaj 《Discrete Mathematics》2009,309(4):834-1274
Let G=(V,E) be a finite, simple and undirected graph. For S⊆V, let δ(S,G)={(u,v)∈E:u∈S and v∈V−S} be the edge boundary of S. Given an integer i, 1≤i≤|V|, let the edge isoperimetric value of G at i be defined as be(i,G)=minS⊆V;|S|=i|δ(S,G)|. The edge isoperimetric peak of G is defined as be(G)=max1≤j≤|V|be(j,G). Let bv(G) denote the vertex isoperimetric peak defined in a corresponding way. The problem of determining a lower bound for the vertex isoperimetric peak in complete t-ary trees was recently considered in [Y. Otachi, K. Yamazaki, A lower bound for the vertex boundary-width of complete k-ary trees, Discrete Mathematics, in press (doi:10.1016/j.disc.2007.05.014)]. In this paper we provide bounds which improve those in the above cited paper. Our results can be generalized to arbitrary (rooted) trees.The depth d of a tree is the number of nodes on the longest path starting from the root and ending at a leaf. In this paper we show that for a complete binary tree of depth d (denoted as ), and where c1, c2 are constants. For a complete t-ary tree of depth d (denoted as ) and d≥clogt where c is a constant, we show that and where c1, c2 are constants. At the heart of our proof we have the following theorem which works for an arbitrary rooted tree and not just for a complete t-ary tree. Let T=(V,E,r) be a finite, connected and rooted tree — the root being the vertex r. Define a weight function w:V→N where the weight w(u) of a vertex u is the number of its successors (including itself) and let the weight index η(T) be defined as the number of distinct weights in the tree, i.e η(T)=|{w(u):u∈V}|. For a positive integer k, let ?(k)=|{i∈N:1≤i≤|V|,be(i,G)≤k}|. We show that . 相似文献
109.
Xianwei Sun 《Discrete Mathematics》2009,309(10):2982-2270
In this paper, we investigate the existence of resolvable group divisible designs (RGDDs) with block size four, group-type hn and general index λ. The necessary conditions for the existence of such a design are n≥4, and . These necessary conditions are shown to be sufficient for all λ≥2, with the definite exceptions of (λ,h,n)∈{(3,2,6)}∪{(2j+1,2,4):j≥1}. The known existence result for λ=1 is also improved. 相似文献
110.
In this paper, we study representations of conformal nets associated with positive definite even lattices and their orbifolds with respect to isometries of the lattices. Using previous general results on orbifolds, we give a list of all irreducible representations of the orbifolds, which generate a unitary modular tensor category. 相似文献