共查询到20条相似文献,搜索用时 46 毫秒
1.
Tiantian Mao 《Journal of multivariate analysis》2010,101(6):1493-1500
Let X1:n≤X2:n≤?≤Xn:n denote the order statistics of random variables X1,X2,…,Xn which are independent but not necessarily identically distributed (INID), and let K1,K2 be two integer-valued random variables, independent of {X1,…,Xn}, such that 1≤K1≤K2≤n. It is shown that if K1 has a log-concave probability function and SI(K2|K1) then RTI(XK2:n|XK1:n), and if K2 has a log-concave probability function and SI(K1|K2) then LTD(XK1:n|XK2:n), where SI, RTI and LTD are three notions of bivariate positive dependence. Based on these, we obtain that RTI and LTD whenever 1≤i<j≤m, where are progressive Type-II censored order statistics from INID random variables {X1,…,Xn}. Furthermore, one result concerning the likelihood ratio ordering of the progressive Type-II censored order statistics is also given. 相似文献
2.
Let K(G) for a finite graph G with vertices v1,...,vn denote the K-algebra with generators X1,...,Xn and defining relations XiXj=XjXi if and only if vi is not connected to vj by an edge in G. We describe centralizers of monomials, show that the centralizer of a monomial is again a graph algebra, prove a unique factorization theorem for factorizations of monomials into commuting factors, compute the homology of K(G), and show that K(G) is the homology ring of a certain loop space. We also construct a K(π, 1) explicitly where π is the group with generators X1,...,Xn and defining relations XiXj=XjXi if and only if vi is not connected to vj by an edge in G. 相似文献
3.
Nicholas J. Kuhn 《Advances in Mathematics》2006,201(2):318-378
Let K(n) be the nth Morava K-theory at a prime p, and let T(n) be the telescope of a vn-self map of a finite complex of type n. In this paper we study the K(n)*-homology of Ω∞X, the 0th space of a spectrum X, and many related matters.We give a sampling of our results.Let PX be the free commutative S-algebra generated by X: it is weakly equivalent to the wedge of all the extended powers of X. We construct a natural map
sn(X):LT(n)P(X)→LT(n)Σ∞(Ω∞X)+ 相似文献
4.
《Topology and its Applications》1986,23(3):291-297
Consider the following game played in a locally compact space X: at the nth move, K chooses a compact set Kn⊂X, and then P chooses a point pn∉∪{Ki: i⩽n}. We say K wins ifP's points have no limit point in X. We show that X is metacompact (σ-metacompact) if and only if K has a strategy in this game which depends only on P's last move (and the number of the move). As a corollary we obtain a game characterization of Eberlein compact spaces. We also show that if P is allowed to choose compact sets instead of points, then K has a winning strategy if and only if X is paracompact. 相似文献
5.
《Topology and its Applications》1988,30(2):165-174
In this paper, we introduce the notion of property [K]1 which implies property [K], and we show the following: Let X be a continuum and let ω be any Whitney map for C(X). Then the following are equivalent. (1) X has property [K]1. (2) C(X) has property [K]1. (3) The Whitney continuum ω−1(t) (0⩽t<ω(X)) has property [K]1.As a corollary, we obtain that if a continuum X has property [K]1, then C(X) has property [K] and each Whitney continuum in C(X) has property [K]. These are partial answers to Nadler's question and Wardle's question ([10, (16.37)] and [11, p. 295]).Also, we show that if each continuum Xn (n=1,2,3,…) has property [K]1, then the product ∏Xn has property [K]1, hence C(∏Xn) and each Whitney continuum have property [K]1. It is known that there exists a curve X such that X has property [K], but X×X does not have property [K] (see [11]). 相似文献
6.
Let Kn denote the set of all n × n nonnegative matrices whose entries have sum n, and let ϕ be a real function on Kn defined by ϕ (X) = Πni=1Σnj=1xij + Πnj=1Σni=1xij − per X for X = [xij] ϵ Kn. A matrix A ϵ Kn is called a ϕ -maximizing matrix on Kn if ϕ (A) ⩾ ϕ (X) for all X ϵ Kn. It is conjectured that Jn = [1/n]n × n is the unique ϕ-maximizing matrix on Kn. In this note, the following are proved: (i) If A is a positive ϕ-maximizing matrix, then A = Jn. (ii) If A is a row stochastic ϕ-maximizing matrix, then A = Jn. (iii) Every row sum and every column sum of a ϕ-maximizing matrix lies between 1 − √2·n!/nn and 1 + (n − 1)√2·n!/nn. (iv) For any p.s.d. symmetric A ϵ Kn, ϕ (A) ⩽ 2 − n!/nn with equality iff A = Jn. (v) ϕ attains a strict local maximum on Kn at Jn. 相似文献
7.
Daria Michalik 《Topology and its Applications》2010,157(7):1228-1236
We prove that there is the universal space for the class of n-dimensional separable metric spaces in the Cartesian product K1×?×Kn+1 of Peano curves without free arcs. It is also shown that the set of embeddings of any n-dimensional separable metric space X into this universal space is a residual set in C(X,K1×?×Kn+1). Other properties of product of Peano curves without free arcs are also proved. 相似文献
8.
Bojan Magajna 《Journal of Functional Analysis》2005,219(2):306-339
For an operator bimodule X over von Neumann algebras A⊆B(H) and B⊆B(K), the space of all completely bounded A,B-bimodule maps from X into B(K,H), is the bimodule dual of X. Basic duality theory is developed with a particular attention to the Haagerup tensor product over von Neumann algebras. To X a normal operator bimodule Xn is associated so that completely bounded A,B-bimodule maps from X into normal operator bimodules factorize uniquely through Xn. A construction of Xn in terms of biduals of X, A and B is presented. Various operator bimodule structures are considered on a Banach bimodule admitting a normal such structure. 相似文献
9.
《Topology and its Applications》1987,26(1):33-41
The main result of this paper is the following extension of an embedding theorem by Nagata: given a sequence of zero-dimensional sets X1,X2,… in a metrizable space X of weight τ⩾ℵ0, the set of homeomorphic embeddings h of X into S(τ)ℵ0, satisfying h(Xn)⊂Kn-1(τ) for n= 1,2,…, is dense in the function space of all continuous mappings of X into S(τ)ℵ0, where Kn(τ) is the n-dimensional universal Nagata's space in the countable product of the star-space S(τ) of weight τ. This seems to be a new result even in the separable case τ=χ0 and provides in particular an answer to a question asked by Kuratowski (see Remark 2.6 for the details). 相似文献
10.
Risong Li 《Communications in Nonlinear Science & Numerical Simulation》2012,17(7):2815-2823
Let f : X → X be a continuous map of a compact metric space X. The map f induces in a natural way a map fM on the space M(X) of probability measures on X, and a transformation fK on the space K(X) of closed subsets of X. In this paper, we show that if (X, f) is a chain transitive system with shadowing property, then exactly one of the following two statements holds:
- (a)
- fn and (fK)n are syndetically sensitive for all n ? 1.
- (b)
- fn and (fK)n are equicontinuous for all n ? 1.
11.
Let Kn denote the set of all n X n nonnegative matrices whose entries have sum n, and let φ be a real valued function defined on Kn by φ(X) = πin=1 n, + πj=1cj−n per X for X E Kn with row sum vector (r1,…, rn) and column sum vector (cl,hellip;, cn). For the same X, let φij(X)= πk≠irk + π1≠jc1 - per X(i| j). A ϵKn is called a φ-maximizing matrix if φ(A) > φ(X) for all X ϵ Kn. Dittert's conjecture asserts that Jn = [1/n]n×n is the unique (φ-maximizing matrix on Kn. In this paper, the following are proved: (i) If A = [aij] is a φ-maximizing matrix on Kn then φij(A) = φ (A) if aij > 0, and φij (A) ⩽ φ (A)if aij = 0. (ii) The conjecture is true for n = 3. 相似文献
12.
Yoshiaki Fukuma 《Journal of Pure and Applied Algebra》2007,211(3):609-621
Let (X,L) be a polarized manifold of dimension n defined over the field of complex numbers. In this paper, we treat the case where n=3 and 4. First we study the case of n=3 and we give an explicit lower bound for h0(KX+L) if κ(X)≥0. Moreover, we show the following: if κ(KX+L)≥0, then h0(KX+L)>0 unless κ(X)=−∞ and h1(OX)=0. This gives us a partial answer of Effective Non-vanishing Conjecture for polarized 3-folds. Next for n=4 we investigate the dimension of H0(KX+mL) for m≥2. If n=4 and κ(X)≥0, then a lower bound for h0(KX+mL) is obtained. We also consider a conjecture of Beltrametti-Sommese for 4-folds and we can prove that this conjecture is true unless κ(X)=−∞ and h1(OX)=0. Furthermore we prove the following: if (X,L) is a polarized 4-fold with κ(X)≥0 and h1(OX)>0, then h0(KX+L)>0. 相似文献
13.
Richard L. Tweedie 《Stochastic Processes and their Applications》1975,3(4):385-403
Let {Xn} be a ?-irreducible Markov chain on an arbitrary space. Sufficient conditions are given under which the chain is ergodic or recurrent. These extend known results for chains on a countable state space. In particular, it is shown that if the space is a normed topological space, then under some continuity conditions on the transition probabilities of {Xn} the conditions for ergodicity will be met if there is a compact set K and an ? > 0 such that whenever x lies outside K and is bounded, x ∈ K; whilst the conditions for recurrence will be met if there exists a compact K with for all x outside K. An application to queueing theory is given. 相似文献
14.
Boris Shekhtman 《Constructive Approximation》1985,1(1):297-303
Let (X n ) be an increasing sequence ofn-dimensional subspaces inL ∞. LetP n be a sequence of projections fromL 1 orL t8 ontoX n , written in the integral form(p n f)(t)=∫K n (s,t)f(s)ds. We prove that if ∥K n ?K n?1∥∞<0(logn), then sup∥p n ∥=∞. This theorem extends some results of Olevskii [3] and Kwapien and Szarek [2]. 相似文献
15.
Mohammad Sal Moslehian Dorian Popa 《Nonlinear Analysis: Theory, Methods & Applications》2010,73(9):2792-2799
Suppose that X is a sequentially complete Hausdorff locally convex space over a scalar field K, V is a bounded subset of X, (an)n≥0 is a sequence in K?{0} with the property lim infn→∞|an|>1, and (bn)n≥0 is a sequence in X. We show that for every sequence (xn)n≥0 in X satisfying
16.
《Journal de Mathématiques Pures et Appliquées》2003,82(1):1-42
We consider holomorphic differential operators on a compact Riemann surface X whose symbol is an isomorphism. Such a differential operator of order n on a vector bundle E sends E to K⊗nX⊗E, where KX is the holomorphic cotangent bundle. We classify all those holomorphic vector bundles E over X that admit such a differential operator. The space of all differential operators whose symbol is an isomorphism is in bijective correspondence with the collection of pairs consisting of a flat vector bundle E over X and a holomorphic subbundle of E satisfying a transversality condition with respect to the connection. 相似文献
17.
Francisco Durango José L. Fernández Pablo Fernández María J. González 《Israel Journal of Mathematics》2016,214(2):983-994
Any (measurable) function K from Rn to R defines an operator K acting on random variables X by K(X) = K(X1,..., Xn), where the Xj are independent copies of X. The main result of this paper concerns continuous selectors H, continuous functions defined in Rn and such that H(x1, x2,..., xn) ∈ {x1, x2,..., xn}. For each such continuous selector H (except for projections onto a single coordinate) there is a unique point ωH in the interval (0, 1) so that, for any random variable X, the iterates H(N) acting on X converge in distribution as N → ∞ to the ωH-quantile of X. 相似文献
18.
E. Nage 《P-Adic Numbers, Ultrametric Analysis, and Applications》2012,4(4):271-305
Let ?? be a natural number. A function f: ? p ?? K into a non-Archimedeanly valued complete field K ? ? p is ??-times continuously differentiable if and only if its Mahler coefficients (a n ) n??? obey |a n |n ?? ?? 0 as n ?? ??. For a real number r ?? 0, this suggests the ad hoc definition by [1] of a C r -function f: ? p ?? K by asking its Mahler coefficients (a n ) n??? to satisfy |a n |n r ?? 0 as n?? ??. We will present for functions f: X ?? K on subsets X ? K without isolated points a general pointwise notion of r-fold differentiability through iterated difference quotients, subsequently shown on the domain X = ? p to coincide with the one given above. For functions on open domains, we prove this notion to admit a handier characterization by its Taylor polynomial up to degree ?r?. 相似文献
19.
Jean-Luc Chabert 《Monatshefte für Mathematik》1983,95(3):181-195
We extend Hilbert's Nullstellensatz by replacing the fieldK by an integral domainA and the polynomial ringK[X 1,...,X n ] by the ring of integral-valued polynomials with respect toA. Necessary and sufficient conditions onA are given so that this generalized version holds. 相似文献
20.
Rafael Dahmen 《Mathematische Zeitschrift》2010,266(1):115-140
We give a sufficient criterion for complex analyticity of nonlinear maps defined on direct limits of normed spaces. This tool is then used to construct new classes of (real and complex) infinite dimensional Lie groups: The group DiffGerm (K, X) of germs of analytic diffeomorphisms around a compact set K in a Banach space X and the group ${\bigcup_{n\in\mathbb {N}}G_n}We give a sufficient criterion for complex analyticity of nonlinear maps defined on direct limits of normed spaces. This tool
is then used to construct new classes of (real and complex) infinite dimensional Lie groups: The group DiffGerm (K, X) of germs of analytic diffeomorphisms around a compact set K in a Banach space X and the group
èn ? \mathbb NGn{\bigcup_{n\in\mathbb {N}}G_n} where the G
n
are Banach Lie groups. 相似文献