共查询到20条相似文献,搜索用时 15 毫秒
1.
We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every variable in this sequence belong to Ac or A1c uniformly. 相似文献
2.
Zhi Xiang Wu 《数学学报(英文版)》2009,25(8):1337-1352
We define a new kind quantized enveloping algebra of a generalized Kac-Moody algebra by adding a new generator J satisfying jm = j for some integer m. We denote this algebra by wUqT(A). This algebra is a weak Hopf algebra if and only if m = 2,3. In general, it is a bialgebra, and contains a Hopf subalgebra. This Hopf subalgebra is isomorphic to the usual quantum envelope algebra Uq (A) of a generalized Kac-Moody algebra A. 相似文献
3.
Li Ping Huang 《数学学报(英文版)》2009,25(9):1517-1528
Let F be a field with |F| ≥ 3, Km be the set of all m × m (m ≥ 4) alternate matrices over F. The arithmetic distance of A, B ∈ Km is d(A, B) := rank(A - B). If d(A, B) = 2, then A and B are said to be adjacent. The diameter of Km is max{d(A, B) : A, B ∈ km}. Assume that φ : Km→Km is a map. We prove the following are equivalent: (a) φ is a diameter preserving surjection in both directions, (b) φ is both an adjacency preserving surjection and a diameter preserving map, (c) φ is a bijective map which preserves the arithmetic distance. 相似文献
4.
In this paper, we study selfinjective Koszul algebras of finite complexity. We prove that the complexity is a nonnegative integer when it is finite; and that the category Yt of modules with complexity less or equal to t, is resolving and coresolving. We show that for each 0 ≤ 1 ≤ m there exist a family of modules of complexity 1 parameterized by G(l, m), the Grassmannian of l-dimensional subspaces of an m-dimensional vector space V, for the exterior algebra of V. Using complexity, we also give a new approach to the representation theory of a tame symmetric algebra with vanishing radical cube over an algebraically closed field of characteristic 0, via skew group algebra of a finite subgroup of SL(2, C) over the exterior algebra of a 2-dimensional vector space. 相似文献
5.
Yu LI 《数学学报(英文版)》2008,24(2):285-304
Let G be a Lie group whose Lie algebra g is quadratic. In the paper "the non-commutative Weil algebra", Alekseev and Meinrenken constructed an explicit G-differential space homomorphism £, called the quantization map, between the Well algebra Wg = S(g^*) χ∧A(g^*) and Wg= U(g) χ Cl(g) (which they call the noncommutative Weil algebra) for g. They showed that £ induces an algebra isomorphism between the basic cohomology rings Hbas^*(Wg) and Hbas^*(Wg). In this paper, we will interpret the quantization map .~ as the super Duflo map between the symmetric algebra S(Tg[1]) and the universal enveloping algebra U(Tg[1]) of a super Lie algebra T9[1] which is canonically associated with the quadratic Lie algebra g. The basic cohomology rings Hbas^*(Wg) and Hbas^*(Wg) correspond exactly to S(Tg[1])^inv and U(Tg[1])^inv, respectively. So what they proved is equivalent to the fact that the super Duflo map commutes with the adjoint action of the super Lie algebra, and that the super Duflo map is an algebra homomorphism when restricted to the space of invariants. 相似文献
6.
Jia Feng Lü 《数学学报(英文版)》2009,25(6):1015-1030
The so-called weakly d-Koszul-type module is introduced and it turns out that each weakly d-Koszul-type module contains a d-Koszul-type submodule. It is proved that, M ∈ W H J^d(A) if and only if M admits a filtration of submodules: 0 belong to U0 belong to U1 belong to ... belong to Up = M such that all Ui/Ui-1 are d-Koszul-type modules, from which we obtain that the finitistic dimension conjecture holds in W H J^d(A) in a special case. Let M ∈ W H J^d(A). It is proved that the Koszul dual E(M) is Noetherian, Hopfian, of finite dimension in special cases, and E(M) ∈ gr0(E(A)). In particular, we show that M ∈ W H J^d(A) if and only if E(G(M)) ∈ gr0(E(A)), where G is the associated graded functor. 相似文献
7.
De Xu Zhou 《数学学报(英文版)》2009,25(9):1567-1582
Assume that S is an almost excellent extension of R. Using functors HomR(S,-) and -×R S, we establish some connections between classes of modules lR and lS, cotorsion pairs (AR, BR) and (AS, BS). If lS is a T-extension or (and) H-extension of lR, we show that lS is a (resp., monomorphic, epimorphic, special) preenveloping class if and only if so is lR. If (AS, BS) is a TH- extension of (AR, BR), we obtain that (AS, BS) is complete (resp., of finite type, of cofinite type, hereditary, perfect, n-tilting) if and only if so is (AR, BR). 相似文献
8.
Let m and n be fixed, positive integers and P a space composed of real polynomials in m variables. The authors study functions f : R →R which map Gram matrices, based upon n points of R^m, into matrices, which are nonnegative definite with respect to P Among other things, the authors discuss continuity, differentiability, convexity, and convexity in the sense of Jensen, of such functions 相似文献
9.
Yu Cheng Li 《数学学报(英文版)》2008,24(10):1737-1750
In this paper, using the matrix skills and operator theory techniques we characterize the commutant of analytic Toeplitz operators on Bergman space. For f(z) = z^ng(z) (n ≥1), g(z) = b0 + b1z^p1 +b2z^p2 +.. , bk ≠ 0 (k = 0, 1, 2,...), our main result is =A′(Mf) = A′(Mzn)∩A′(Mg) = A′(Mz^s), where s = g.c.d.(n,p1,p2,...). In the last section, we study the relation between strongly irreducible curve and the winding number W(f,f(α)), α ∈ D. 相似文献
10.
Let Q be the quaternion Heisenberg group,and let P be the affine automorphism group of Q.We develop the theory of continuous wavelet transform on the quaternion Heisenberg group via the unitary representations of P on L2(Q).A class of radial wavelets is constructed.The inverse wavelet transform is simplified by using radial wavelets.Then we investigate the Radon transform on Q.A Semyanistyi–Lizorkin space is introduced,on which the Radon transform is a bijection.We deal with the Radon transform on Q both by the Euclidean Fourier transform and the group Fourier transform.These two treatments are essentially equivalent.We also give an inversion formula by using wavelets,which does not require the smoothness of functions if the wavelet is smooth.In addition,we obtain an inversion formula of the Radon transform associated with the sub-Laplacian on Q. 相似文献
11.
Given a graphing
of a countable Borel equivalence relation on a Polish space, we show that if there is a Borel way of selecting a non-empty
closed set of countably many ends from each
-component, then there is a Borel way of selecting an end or line from each
-component. Our method yields also Glimm-Effros style dichotomies which characterize the circumstances under which: (1) there
is a Borel way of selecting a point or end from each
-component; and (2) there is a Borel way of selecting a point, end or line from each
-component.
The first author was supported in part by NSF Grant DMS-0140503.
The second author was supported in part by NSF VIGRE Grant DMS-0502315. 相似文献
12.
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
13.
Tao Hao 《数学学报(英文版)》2010,26(7):1345-1354
In this paper, we introduce the notion of g-variance and study some properties of this operator. We find the nonlinear variance operator, g-variance, does not preserve some basic properties of traditional mathematic variance. We also consider the relationship Dμ[ξ] and supQe T^1 VarQ[ξ] (D-μ [ξ] and infQe T^1 VarQ [ξ]). The result shows that the maximum (minimum) variance is not always equal to Dμ[·] (D-μ[·]). If g satisfies some restrictive conditions, we get the uniqueness theorem and the comparison theorem via g-variance. 相似文献
14.
Cheng Jun Hou 《数学学报(英文版)》2008,24(6):983-996
We introduce two notions of the pressure in operator algebras, one is the pressure Pα(π, T) for an automorphism α of a unital exact C^*-algebra A at a self-adjoint element T in A with respect to a faithful unital *-representation π the other is the pressure Pτ,α(T) for an automorphism α of a hyperfinite von Neumann algebra M at a self-adjoint element T in M with respect to a faithful normal α-invariant state τ. We give some properties of the pressure, show that it is a conjugate invaxiant, and also prove that the pressure of the implementing inner automorphism of a crossed product A×α Z at a self-adjoint operator T in A equals that of α at T. 相似文献
15.
Ján Jakubík 《Czechoslovak Mathematical Journal》2009,59(1):183-196
In this paper we deal with a pseudo effect algebra
possessing a certain interpolation property. According to a result of Dvurečenskij and Vettterlein,
can be represented as an interval of a unital partially ordered group G. We prove that
is projectable (strongly projectable) if and only if G is projectable (strongly projectable). An analogous result concerning weak homogeneity of
and of G is shown to be valid.
This work has been partially supported by the Slovak Academy of Sciences via the project Center of Excellence—Physics of Information
(grant I/2/2005). 相似文献
16.
17.
Sergiy Maksymenko 《Central European Journal of Mathematics》2009,7(2):272-298
Let F be a C
∞ vector field defined near the origin O ∈ ℝ
n
, F(O) = 0, and (F
t
) be its local flow. Denote by
the set of germs of orbit preserving diffeomorphisms h: ℝ
n
→ ℝ
n
at O, and let
, (r ≥ 0), be the identity component of
with respect to the weak Whitney W
r
topology. Then
contains a subset
consisting of maps of the form F
α(x)(x), where α: ℝ
n
→ ℝ runs over the space of all smooth germs at O. It was proved earlier by the author that if F is a linear vector field, then
=
.
In this paper we present a class of examples of vector fields with degenerate singularities at O for which
formally coincides with
, i.e. on the level of ∞-jets at O.
We also establish parameter rigidity of linear vector fields and “reduced” Hamiltonian vector fields of real homogeneous polynomials
in two variables.
相似文献
18.
19.
20.
In this paper,we give a relationship between projective generators(resp.,injective cogenerators) in the category of R-modules and the counterparts in the category of complexes of R-modules.As a consequence,we get that complexes of W-Gorenstein modules are actually W-Gorenstein complexes whenever W is a subcategory of R-modules satisfying W⊥W,where W is the subcategory of exact complexes with all cycles in W.We also study when all cycles of a W-Gorenstein complexes are W-Gorenstein modules. 相似文献