共查询到20条相似文献,搜索用时 109 毫秒
1.
Yong Feng PANG Wei YANG Hong Ke DU .Department of Mathematics School of Science Xi’an University of Architecture Technology Shaanxi P.R.China .College of Mathematics Information Science Shaanxi Normal University Shaanxi 《数学研究与评论》2011,31(4)
Let D = {{0},K,L,M,X } be a strongly double triangle subspace lattice on a non- zero complex reflexive Banach space X ,which satisfies that one of three sums K + L,L + M and M + K is closed.It is shown that local φ-derivations and φ-derivations at zero point on AlgD are generalized φ-derivations. 相似文献
2.
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
3.
Huai Liang Chang 《数学学报(英文版)》2014,30(12):2079-2084
Let S be a smooth algebraic surface and let L be a line bundle on S.Suppose there is a holomorphic two form over S with zero loci to be a curve C.We show that the DonaldsonThomas invariant of the P^1 scroll X = P(L+Бs) vanishes unless the curves being enumerated lie in D = P(L︱C+БC).Our method is cosection localization of Y.-H.Kiem and J.Li. 相似文献
4.
In this paper, we study (α,β)-metrics of scalar flag curvature on a manifold M of dimension n (n 〉 3). Suppose that an (α,β)-metric F is not a Finsler metric of Randers type, that is, F ≠k1 V√α^2 + k2β^2 + k3β, where k1 〉 0, k2 and k3 are scalar functions on M. We prove that F is of scalar flag curvature and of vanishing S-curvature if metric. In this case, F is a locally Minkowski and only if the flag curvature K = 0 and F is a Berwald metric. 相似文献
5.
Characterizations and Extensions of Lipschitz-α Operators 总被引:1,自引:0,他引:1
Huai Xin CAO Jian Hua ZHANG Zong Ben XU 《数学学报(英文版)》2006,22(3):671-678
In this work, we prove that a map F from a compact metric space K into a Banach space X over F is a Lipschitz-α operator if and only if for each σ in X^* the map σoF is a Lipschitz-α function on K. In the case that K = [a, b], we show that a map f from [a, b] into X is a Lipschitz-1 operator if and only if it is absolutely continuous and the map σ→ (σ o f)' is a bounded linear operator from X^* into L^∞([a, b]). When K is a compact subset of a finite interval (a, b) and 0 〈 α ≤ 1, we show that every Lipschitz-α operator f from K into X can be extended as a Lipschitz-α operator F from [a, b] into X with Lα(f) ≤ Lα(F) ≤ 3^1-α Lα(f). A similar extension theorem for a little Lipschitz-α operator is also obtained. 相似文献
6.
Let M be a convex Chebyshev subset of a uniformly convex and uniformly smoothBanach space.It is proved that the metric projection P_M of X onto M is uniformly continu-ous on every bounded subset of X.Moreover,a global and explicit estimate on the modulus ofcontinuity of the metric projection is obtained. 相似文献
7.
For an additive subgroup G of a field F of characteristic zero, a Lie algebra B(G) of Block type is defined with basis {Lα,i| α∈G, i∈Z+} and relations [Lα,i, Lβ,j] = (β-α)Lα+β,i+j+(αj-βi)Lα+β,Lα+β,i+j-1.It is proved that an irreducible highest weight B(Z)-module is quasifinite if and only if it is a proper quotient of a Verma module. Furthermore, for a total order λ on G and any ∧∈B(G)0^*(the dual space of B(G)0 = span{L0,i|i∈Z+}), a Verma B(G)-module M(∧,λ) is defined, and the irreducibility of M(A,λ) is completely determined. 相似文献
8.
Yi Bing SHEN Xiao Hua ZHU 《数学学报(英文版)》2005,21(3):631-642
By using curvature estimates, we prove that a complete non-compact hypersurface M with constant mean curvature and finite L^n-norm curvature in R^1+1 must be minimal, so that M is a hyperplane if it is strongly stable. This is a generalization of the result on stable complete minimal hypersurfaces of R^n+1. Moreover, complete strongly stable hypersurfaces with constant mean curvature and finite L^1-norm curvature in R^1+1 are considered. 相似文献
9.
Let X be a C~1 vector field on a compact boundaryless Riemannian manifold M(dim M≥2),and A a compact invariant set of X.Suppose that A has a hyperbolic splitting,i.e.,T∧M = E~sX E~u with E~s uniformly contracting and E~u uniformly expanding.We prove that if,in addition,A is chain transitive,then the hyperbolic splitting is continuous,i.e.,A is a hyperbolic set.In general,when A is not necessarily chain transitive,the chain recurrent part is a hyperbolic set.Furthermore,we show that if the whole manifold M admits a hyperbolic splitting,then X has no singularity,and the flow is Anosov. 相似文献
10.
Let R be a prime ring with a non-central Lie ideal L. In the present paper we show that if the composition DG of two generalized derivations D and G is zero on L, then DG must be zero on R. And we get all the possibilities for the composition of a couple of generalized derivations to be zero on a non-central Lie ideal of a prime ring. 相似文献
11.
Let =(A C X B)be a 2×2 operator matrix acting on the Hilbert space н( )κ.For given A ∈B (H),B ∈B(K)and C ∈B(K,H)the set Ux∈B(H,к)σe(Mx)is determined,where σe(T)denotes the essential spectrum. 相似文献
12.
Piotr Zakrzewski 《Proceedings of the American Mathematical Society》2001,129(1):271-278
We prove that if ZFC is consistent so is ZFC + ``for any sequence of subsets of a Polish space there exists a separable metrizable topology on with , and Borel in for all .' This is a category analogue of a theorem of Carlson on the possibility of extending Lebesgue measure to any countable collection of sets. A uniform argument is presented, which gives a new proof of the latter as well.
Some consequences of these extension properties are also studied.
13.
在已有研究中,对于$p$-子群的正规化子而言,它的$p$-幂零性质对有限$p$-幂零群的结构具有重要的影响. 本文中, 设$P$是群$G$的西罗$p$-子群, $1\leq p^d<|P|$, 对于$P$的每个阶为$p^d$的正规子群$H$H,将$N_G(H)$的$p$-幂零性质减弱为$p$-超可解性质,结合$H$的弱$M$-可补充性质,探究$p$-超可解群的结构.同时,在$N_G(P)$是$p$-幂零的条件下,利用子群$K$的弱$M$-可补充条件研究群的$p$-幂零性质,其中$K_p\leq K$且$P''\leq K_p\leq \Phi(P)$. $K_p$是$K$的西罗$p$-子群.在一定程度上,主要结果推广了Frobenius定理. 相似文献
14.
D.M. Speegle 在文献[1] 中给出了具有常数 $\alpha$的性质${\cal A}$ 的定义,并且证明了任意无限维的可分一致光滑Banach空间都具有这样的性质,而且常数 $\alpha\in [0,1)$.本文给出了一个使得无限维可分Banach空间具有这种性质的充分条件,以及几个关于文献[1] 的注解. 相似文献
15.
Brooks Roberts 《Transactions of the American Mathematical Society》1999,351(2):781-811
In this paper we consider the theta correspondence between the sets and when is a nonarchimedean local field and . Our main theorem determines all the elements of that occur in the correspondence. The answer involves distinguished representations. As a corollary, we characterize all the elements of that occur in the theta correspondence between and . We also apply our main result to prove a case of a new conjecture of S.S. Kudla concerning the first occurrence of a representation in the theta correspondence.
16.
The $\mathbb{Z}_{+}$-ring is an important invariant in the theory of tensor category. In this paper, by using matrix method, we describe all irreducible $\mathbb{Z}_{+}$-modules over a $\mathbb{Z}_{+}$-ring $\mathcal{A}$, where $\mathcal{A}$ is a commutative ring with a $\mathbb{Z}_{+}$-basis{$1$, $x$, $y$, $xy$} and relations: $$ x^{2}=1,\;\;\;\;\; y^{2}=1+x+xy.$$We prove that when the rank of $\mathbb{Z}_{+}$-module $n\geq5$, there does not exist irreducible $\mathbb{Z}_{+}$-modules and when the rank $n\leq4$, there exists finite inequivalent irreducible $\mathbb{Z}_{+}$-modules, the number of which is respectively 1, 3, 3, 2 when the rank runs from 1 to 4. 相似文献
17.
Theodore A. Slaman 《Proceedings of the American Mathematical Society》2004,132(8):2449-2456
Working in the base theory of , we show that for all , the bounding principle for -formulas ( ) is equivalent to the induction principle for -formulas ( ). This partially answers a question of J. Paris.
19.
In this note we define a new topology on C(X),the set of all real-valued continuous functions on a Tychonoff space X.The new topology on C(X) is the topology having subbase open sets of both kinds:[f,C,ε[={g E C(X):|f(x)-g(x)| ε for every x∈C} and[U,r]~-={g∈C(X):g~(-1)(r)∩U≠φ},where f∈C(X),C∈KC(X)={nonempty compact subsets of X},ε 0,while U is an open subset of X and r∈R.The space C(X) equipped with the new topology T_(kh) which is stated above is denoted by C_(kh)(X).Denote X_0={x∈X:x is an isolated point of X} and X_c={x∈X:x has a compact neighborhood in X}.We show that if X is a Tychonoff space such that X_0=X_c,then the following statements are equivalent:(1) X_0 is G_δ-dense in X;(2) C_(kh)(X) is regular;(3) C_(kh)(X) is Tychonoff;(4) C_(kh)(X) is a topological group.We also show that if X is a Tychonoff space such that X_0=X_c and C_(kh)(X) is regular space with countable pseudocharacter,then X is σ-compact.If X is a metrizable hemicompact countable space,then C_(kh)(X) is first countable. 相似文献
20.
{Well-posedness of degenerate differential equations with infinite delay in Holder continuous function spaces 下载免费PDF全文
Using operator-valued $\dot{C}^\alpha$-Fourier multiplier results on vector- valued H\"older continuous function spaces, we give a characterization for the $C^\alpha$-well-posedness of the first order degenerate differential equations with infinite delay $(Mu)"(t) = Au(t) + \int_{-\infty}^t a(t-s)Au(s)ds + f(t)$ ($t\in\R$), where $A, M$ are closed operators on a Banach space $X$ such that $D(A)\cap D(M)\neq \{0\}$, $a\in L^1_{\rm{loc}}(\R_+)\cap L^1(\mathbb{R}_+; t^\alpha dt)$. 相似文献