共查询到20条相似文献,搜索用时 500 毫秒
1.
Zhengxing Li 《代数通讯》2013,41(9):3933-3938
Let N be a finite nontrivial nilpotent group and H a finite centerless permutation group on a finite set Ω (i.e., H acts faithfully on Ω). Let G = N?H = N|Ω| ? H be the corresponding permutational wreath product of N by H. It is shown that every Coleman automorphism of G is an inner automorphism. This generalizes a well-known result due to Petit Lobão and Sehgal stating that the normalizer property holds for complete monomial groups with nilpotent base groups. 相似文献
2.
Heinrich Matzinger 《Random Structures and Algorithms》1999,15(2):196-207
Let {ξ(n)}n∈ℤ be a three‐color random scenery, i.e., a random coloration of ℤ in three colors, such that the colors of the different points in ℕ are i.i.d. Let {S(n)}n∈ℕ be a symmetric random walk starting at 0. Our main result shows that a.s., ξ∘S (the composition of ξ and S) determines ξ up to translation and reflection. In other words, by observing the scenery along the random walk path S, we can a.s. reconstruct ξ up to translation and reflection. This result allows us to give a positive answer to the question of H. Kesten of whether one can a.s. detect a single defect in a three‐color random scenery by observing it only along a random walk path. ©1999 John Wiley & Sons, Inc. Random Struct. Alg., 15, 196–207, 1999 相似文献
3.
R.L Vaughn 《Applicable analysis》2013,92(4):337-348
Let L 0(ΩA,P) be the space of equivalent classes of random variables defined on a probability space (Ω,A,P). Let H be the closed subspace of L 0(Ω,A,P) spanned by a sequence of i.i.d. (independent and identically distributed) random variables having the symmetric nondegenerate law F. It is proved that H is linearly homeomorphic to l p for 0<p≤2 if F belongs to the domain of normal attraction of symmetric stable law withexponent p. 相似文献
4.
Graham Smith 《Geometriae Dedicata》2009,140(1):95-135
Let (M, Q) be a compact, three dimensional manifold of strictly negative sectional curvature. Let (Σ, P) be a compact, orientable surface of hyperbolic type (i.e. of genus at least two). Let θ : π1(Σ, P) → π1(M, Q) be a homomorphism. Generalising a recent result of Gallo, Kapovich and Marden concerning necessary and sufficient conditions
for the existence of complex projective structures with specified holonomy to manifolds of non-constant negative curvature,
we obtain necessary conditions on θ for the existence of a so called θ-equivariant Plateau problem over Σ, which is equivalent to the existence of a strictly convex immersion i : Σ → M which realises θ (i.e. such that θ = i
*).
相似文献
5.
Let G be a finite group not necessarily abelian. We prove a multiplier theorem for a normal partial addition set in G (i.e. a partial addition set which is a union of conjugacy classes).The second author gratefully acknowledges the financial support by the CNR which made this work possible. 相似文献
6.
Sets of Double and Triple Weights of Trees 总被引:1,自引:0,他引:1
Elena Rubei 《Annals of Combinatorics》2011,15(4):723-734
Let T be a weighted tree with n leaves numbered by the set {1, . . . , n}. Let D
i, j
(T) be the distance between the leaves i and j. Let
Di,j,k(T) = \frac12(Di,j(T)+Dj,k(T)+Di,k(T)){{D_{i,j,k}(T) = \frac{1}{2}(D_{i,j}(T)+D_{j,k}(T)+D_{i,k}(T))}} . We will call such numbers “triple weights” of the tree. In this paper, we give a characterization, different from the previous
ones, for sets indexed by 2-subsets of a n-set to be double weights of a tree. By using the same ideas, we find also necessary and sufficient conditions for a set of
real numbers indexed by 3-subsets of an n-set to be the set of the triple weights of a tree with n leaves. Besides we propose a slight modification of Saitou-Nei’s Neighbour-Joining algorithm to reconstruct trees from the
data D
i, j
. 相似文献
7.
Semeon Bogatyi Daciberg L. Gonçalves Heiner Zieschang 《Mathematische Zeitschrift》2001,236(3):419-452
Let be a continuous mapping between orientable closed surfaces of genus h and g and let c denote the constant map with . Let be the minimal number of roots of f' among all maps f' homotopic to f, i.e. . We prove that
where
and denotes the Euler characteristic. In addition, certain quadratic equations in free groups closely related to the coincidence
problem are solved.
Received January 26, 1999; in final form November 8, 1999 / Published online February 5, 2001 相似文献
8.
Wen Jiwei Yan Yunliang 《高校应用数学学报(英文版)》2006,21(1):87-95
Let X,X1,X2 be i. i. d. random variables with EX^2+δ〈∞ (for some δ〉0). Consider a one dimensional random walk S={Sn}n≥0, starting from S0 =0. Let ζ* (n)=supx∈zζ(x,n),ζ(x,n) =#{0≤k≤n:[Sk]=x}. A strong approximation of ζ(n) by the local time for Wiener process is presented and the limsup type and liminf-type laws of iterated logarithm of the maximum local time ζ*(n) are obtained. Furthermore,the precise asymptoties in the law of iterated logarithm of ζ*(n) is proved. 相似文献
9.
M. H. Lim 《Linear and Multilinear Algebra》2013,61(4):333-354
Let G be a subgroup of the symmetric group Sm and V be an n-dimensional unitary space where nm. Let V(G) be the symmetry class of tensors over V associated with G and the identity character. Let D(G) be the set of all decomposable elements of V(G) and O(G) be its subset consisting of all nonzero decomposable tensors x 1 ?…? xm such that {x 1,…,xm } is an orthogonal set. In this paper we study the structure of linear mappings on V(G) that preserve one of the following subsets: (i)O(G), (ii) D(G)\(O(G)?{0}). 相似文献
10.
E. Ballico 《代数通讯》2013,41(13):4113-4122
Let Ebe a rank nvector bundle on a smooth projective curve X. It is known that Emay be obtained from a splitted bundle +1≤i≤ Li;, rank(Li) = 1, by a finite number of elementary transformations. Here we give upper bounds for their minimal number. If n= 2 this is related to the order of stability of E. 相似文献
11.
L. Saloff-Coste 《Journal of Geometric Analysis》2004,14(4):715-733
Let M =G/H be an irreducible homogeneous compact manifold of dimension n equipped with its canonical Riemannian metric. Let γ be
the lowest nonzero eigenvalue of the Laplace operator. Let μ be the normalized Haar measure and μ
t be the heat diffusion measure, i.e., the law of Brownian motion started at a fixed origin in M. We show that the total variation
distance between μt and μ is not small for t ≪λ
−1 logn.This is sharp, up to a factor of two, in the case of compact irreducible simply connected symmetric spaces. 相似文献
12.
13.
Let L be a J-subspace lattice on a Banach space X and Alg L the associated J-subspace lattice algebra. Let A be a standard operator subalgebra (i.e., it contains all finite rank operators in AlgL) of AlgL and M■B(X) the Alg L-bimodule. It is shown that every linear Jordan triple derivation from A into M is a derivation, and that every generalized Jordan (triple) derivation from A into M is a generalized derivation. 相似文献
14.
Let X
i
, i∈N, be i.i.d. B-valued random variables, where B is a real separable Banach space. Let Φ be a mapping B→R. Under a central limit theorem assumption, an asymptotic evaluation of Z
n
= E (exp (n
Φ (∑
i
=1
n
X
i
/n))), up to a factor (1 + o(1)), has been gotten in Bolthausen [1]. In this paper, we show that the same asymptotic evaluation can be gotten without
the central limit theorem assumption.
Received: 19 September 1997 / Revised version:22 April 1999 相似文献
15.
Let Xi, i = 1, 2,…, be i.i.d. symmetric random variables in the domain of attraction of a symmetric stable distribution Gα with 0 < α < 2. Let Yi, i = 1, 2, …, be i.i.d. symmetric stable random variables with the common distribution Gα. It is known that under certain conditions the sequences {Xi} and {Yi} can be reconstructed on a new probability space without changing the distribution of each such that \documentclass{article}\pagestyle{empty}\begin{document}$ \sum\limits_{i = 1}^n {(X_i - Y_i) = o(n^{1/\gamma})} $\end{document} a.s. as n → ∞, where α ≦ γ < 2 (see Stout [10]). We will give a second approximation by partial sums of i.i.d. stable (with characteristic exponent α*, α < α* ≦ 2) random variables Ui, i = 1, 2,…, n, and we will obtain strong upperbounds for the differences \documentclass{article}\pagestyle{empty}\begin{document}$ \sum\limits_{i = 1}^n {(X_i - Y_i - U_i)} $\end{document}. 相似文献
16.
Matteo Dalla Riva Massimo Lanza de Cristoforis 《Complex Analysis and Operator Theory》2011,5(3):811-833
Let Ω
i
and Ω
o
be two bounded open subsets of
\mathbbRn{{\mathbb{R}}^{n}} containing 0. Let G
i
be a (nonlinear) map from
?Wi×\mathbbRn{\partial\Omega^{i}\times {\mathbb{R}}^{n}} to
\mathbbRn{{\mathbb{R}}^{n}} . Let a
o
be a map from ∂Ω
o
to the set
Mn(\mathbbR){M_{n}({\mathbb{R}})} of n × n matrices with real entries. Let g be a function from ∂Ω
o
to
\mathbbRn{{\mathbb{R}}^{n}} . Let γ be a positive valued function defined on a right neighborhood of 0 in the real line. Let T be a map from
]1-(2/n),+¥[×Mn(\mathbbR){]1-(2/n),+\infty[\times M_{n}({\mathbb{R}})} to
Mn(\mathbbR){M_{n}({\mathbb{R}})} . Then we consider the problem
$\left\{ {ll} {{\rm div}}\, (T(\omega,Du))=0 &\quad {{\rm in}} \;\Omega^{o} \setminus\epsilon{{\rm cl}} \Omega^{i},\\ -T(\omega,Du(x))\nu_{\epsilon\Omega^{i}}(x)=\frac{1}{\gamma(\epsilon)}G^{i}({x}/{\epsilon}, \gamma(\epsilon)\epsilon^{-1} ({\rm log} \, \epsilon)^{-\delta_{2,n}} u(x)) & \quad \forall x \in \epsilon\partial\Omega^{i},\\ T(\omega, Du(x)) \nu^{o}(x)=a^{o}(x)u(x)+g(x) & \quad \forall x \in \partial \Omega^{o}, \right.$\left\{ \begin{array}{ll} {{\rm div}}\, (T(\omega,Du))=0 &\quad {{\rm in}} \;\Omega^{o} \setminus\epsilon{{\rm cl}} \Omega^{i},\\ -T(\omega,Du(x))\nu_{\epsilon\Omega^{i}}(x)=\frac{1}{\gamma(\epsilon)}G^{i}({x}/{\epsilon}, \gamma(\epsilon)\epsilon^{-1} ({\rm log} \, \epsilon)^{-\delta_{2,n}} u(x)) & \quad \forall x \in \epsilon\partial\Omega^{i},\\ T(\omega, Du(x)) \nu^{o}(x)=a^{o}(x)u(x)+g(x) & \quad \forall x \in \partial \Omega^{o}, \end{array} \right. 相似文献
17.
Let R be a ring with involution. In this paper, we extend the notions of m-EP matrices and m-EP operators to an arbitrary ring case. A number of new characterizations of m-EP elements in rings are presented. In particular, the existence criteria for 1-EP (i.e. EP) elements are obtained by means of the group inverse, Moore–Penrose inverse, and core inverse. Some properties of 2-EP are also given. 相似文献
18.
Let M be a compact orientable manifold, and F be an essential closed surface which cuts M into two 3-manifolds M
1 and M
2. Let be a Heegaard splitting for i = 1, 2. We denote by d(S
i
) the distance of . If d(S
1), d(S
2) ≥ 2(g(M
1) + g(M
2) − g(F)), then M has a unique minimal Heegaard splitting up to isotopy, i.e. the amalgamation of and .
Ruifeng Qiu is supported by NSFC(10625102). 相似文献
19.
Gabriela Ciuperca 《Annals of the Institute of Statistical Mathematics》2002,54(3):585-594
Let f
0(x) be the exponential density and f
(x) the translation model. Let (X
i)
i=1,n
be i.i.d. random variables, with density g. We test that g is f
0 against g is a simple mixture, using the LRT statistic. We prove that the LRT diverges to infinity with probability 1/2 and it is equal to 0 with probability 1/2. Therefore, the classical likelihood limiting theory does not hold. 相似文献
20.
G. Molteni 《Mathematische Nachrichten》2009,282(2):232-242
Let N ∈ ? and let χ be a Dirichlet character modulo N. Let f be a modular form with respect to the group Γ0(N), multiplier χ and weight k. Let F be the L ‐function associated with f and normalized in such a way that F (s) satisfies a functional equation where s reflects in 1 – s. The modular forms f for which F belongs to the extended Selberg class S# are characterized. For these forms the factorization of F in primitive elements of S# is enquired. In particular, it is proved that if f is a cusp form and F ∈ S# then F is almost primitive (i.e., that if F = PG is a factorization with P, G ∈ S# and the degree of P is < 2 then P is a Dirichlet polynomial). It is also proved that the conductor of the polynomial factor P is bounded by N. If f belongs to the space generated by newforms and N ≤ 4 then F is actually primitive (i.e., P is a constant) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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