共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
设Pn(x)为[0,∞)上次数不超过n的代数多项式,则有‖p′n(x)e-x‖[0,∞)≤(6.3n+1)‖pn(x)e-x‖[0,∞).若pn(x)同时又是奇函数或偶函数,则有‖p′n(x)e-x‖[0,∞)≤(1.8+7n1/2)‖p相似文献
3.
设1
(n-1)/p-n/2,f∈Lp(Ωn),σδN(f)(x)表示f(x)在n-球面Ωn上的Cesàro平均.本文证明了(?)ak≤A(A是绝对常数),这个结果加强了现有的结论. 相似文献
4.
5.
本文我们引入了函数类Bδ(G//K)={φ∈L1(G//K)||φ(t)|≤Δ-1(t)(1+t)1-δ,δ>0),对f∈Lp(G//K),1≤p≤∞,和极大算子(?),证明了这类算子是(H∞,s1,L1)型的. 相似文献
6.
Hp(Rn×R+)(1<p<+∞)函数得渐近行为于70年代已获得整体上的描述,今利用扩张得空间EHp(Rn×R+)的不同层次间的内在关联,给出每个层次Hp函数的具体的渐近行为,以及EHp函数在整体上得渐近行为. 相似文献
7.
In this paper, a derivation δAB mapping into a ideal I of B(H) is considered, when A,B ∈B(H) and I is a norm ideal. If Ran(δAB)?I, let δAB:B(H)→I denote the induced operator and let λ be the scalar such that A- λ∈I, B-λ∈I, we estimate the norm of δAB as follows‖A-λ‖+‖B-λ‖≥‖δAB‖≥‖A- λ‖+‖B-λ‖ when WN(A-λ)∩WN(λ - B)≠?, where WN(A- λ) denotes the normalized maximal numerical range and ‖A-λ‖ denotes the norm of A-λ∈I. In particular when I=Cp(l
p, we prove that ‖δAB‖p=‖A-λ‖p+‖B-λ‖p if and only if ‖A-λ‖=‖A-λ‖p and WN(A-λ)∩WN(λ-B)≠?. At last, some examples show that the estimate as above is exact. 相似文献
8.
9.
假设 β1 > 3α1 > 0, β2 > 3α2 > 0,给定函数f(x) ∈ S(R3), 定义算子Tα,β如下:Tα,βf(x,y,z) = p.v.ZTQ2f(x- t, y-s, z-γ(t)h(s)) e-2πit-β1 s-β2/t1+α1 s1+α2dtds.本文主要考虑如上定义的算子Tα,β在Lebesgue空间Lp(R3)及Wiener共合空间W(FLp, Lq)(R3)上的有界性. 这里 Q2 = [0, 1] × [0, 1], γ(t), h(s)满足适当的条件.作为应用, 本文还考虑了带粗糙核的奇异积分算子在乘积空间上的有界性. 相似文献
10.
本文讨论了δ-Calderon-Zygmund算子以及θ(t)-Calderon-Zygmund算子在Hardy型空间CHpq上的有界性. 相似文献
11.
We investigate when the set of finite products of distinct terms of a sequence 〈x
n
〉
n=1∞ in a semigroup (S,⋅) is large in any of several standard notions of largeness. These include piecewise syndetic, central, syndetic, central*, and IP*. In the case of a “nice” sequence in (S,⋅)=(ℕ,+) one has that FS(〈x
n
〉
n=1∞) has any or all of the first three properties if and only if {x
n+1−∑
t=1
n
x
t
:n∈ℕ} is bounded from above.
N. Hindman acknowledges support received from the National Science Foundation via Grant DMS-0554803. 相似文献
12.
《随机分析与应用》2013,31(4):785-808
Abstract We study the queue length of the M X /G/1 queue under D-policy. We derive the queue length PGF at an arbitrary point of time. Then, we derive the mean queue length. As special cases, M/G/1, M X /M/1, and M/M/1 queue under D-policy are investigated. Finally, the effects of employing D-policy are discussed. 相似文献
13.
María Burgos Antonio M. Peralta 《Journal of Mathematical Analysis and Applications》2011,376(1):221-230
We prove that every biorthogonality preserving linear surjection between two dual or compact C?-algebras or between two von Neumann algebras is automatically continuous. 相似文献
14.
Najla A. Altwaijry 《Journal of Functional Analysis》2008,254(11):2866-2892
The Banach-Lie algebra L(A) of multiplication operators on the JB∗-triple A is introduced and it is shown that the hermitian part Lh(A) of L(A) is a unital GM-space the base of the dual cone in the dual GL-space ∗(Lh(A)) of which is affine isomorphic and weak∗-homeomorphic to the state space of L(A). In the case in which A is a JBW∗-triple, it is shown that tripotents u and v in A are orthogonal if and only if the corresponding multiplication operators in the unital GM-space Lh(A) satisfy
0?D(u,u)+D(v,v)?idA, 相似文献
15.
Existence and regularity of solutions to model for liquid mixture of 3He-4He is considered in this paper. First, it is proved that this system possesses a unique global weak solution in H1(ω,C×R) by using Galerkin method. Secondly, by using an iteration procedure, regularity estimates for the linear semigroups, it is proved that the model for liquid mixture of 3He-4He has a unique solution in Hk(ω,C×R) for all k ≥ 1. 相似文献
16.
The paper aims at developing a theory of nuclear (in the topological algebraic sense) pro-C*-algebras (which are inverse limits of C*-algebras) by investigating completely positive maps and tensor products. By using the structure of matrix algebras over a
pro-C*-algebra, it is shown that a unital continuous linear map between pro-C*-algebrasA andB is completely positive iff by restriction, it defines a completely positive map between the C*-algebrasb(A) andb(B) consisting of all bounded elements ofA andB. In the metrizable case,A andB are homeomorphically isomorphic iff they are matricially order isomorphic. The injective pro-C*-topology α and the projective pro-C*-topology v on A⊗B are shown to be minimal and maximal pro-C*-topologies; and α coincides with the topology of biequicontinous convergence iff eitherA orB is abelian. A nuclear pro-C*-algebraA is one that satisfies, for any pro-C*-algebra (or a C*-algebra)B, any of the equivalent requirements; (i) α =v onA ⊗B (ii)A is inverse limit of nuclear C*-algebras (iii) there is only one admissible pro-C*-topologyon A⊗B (iv) the bounded partb(A) ofA is a nuclear C⊗-algebra (v) any continuous complete state map A→B* can be approximated in simple weak* convergence by certain finite rank complete state maps. This is used to investigate permanence properties of nuclear pro-C*-algebras pertaining to subalgebras, quotients and projective and inductive limits. A nuclearity criterion for multiplier
algebras (in particular, the multiplier algebra of Pedersen ideal of a C*-algebra) is developed and the connection of this C*-algebraic nuclearity with Grothendieck’s linear topological nuclearity is examined. A σ-C*-algebraA is a nuclear space iff it is an inverse limit of finite dimensional C*-algebras; and if abelian, thenA is isomorphic to the algebra (pointwise operations) of all scalar sequences. 相似文献
17.
Chunhong FU 《数学年刊B辑(英文版)》2023,44(3):325-344
Motivated by two norm equations used to characterize the Friedrichs angle, this paper studies C*-isomorphisms associated with two projections by introducing the matched triple and the semi-harmonious pair of projections. A triple (P, Q, H) is said to be matched if H is a Hilbert C*-module, P and Q are projections on H such that their infimum P ∧ Q exists as an element of L(H), where L(H) denotes the set of all adjointable operators on H. The C*-subalgebras of L(H) generated by elements in {P - P ∧ Q, Q - P ∧ Q, I} and {P, Q, P ∧ Q, I} are denoted by i(P, Q, H) and o(P, Q, H), respectively. It is proved that each faithful representation (π, X) of o(P, Q, H) can induce a faithful representation (π, X e) of i(P, Q, H) such that e π(P - P ∧ Q) = π(P) - π(P) ∧ π(Q),eπ(Q - P ∧ Q) = π(Q) - π(P) ∧ π(Q).When (P, Q) is semi-harmonious, that is, R(P + Q) and R(2I - P - Q) are both orthogonally complemented in H, it is shown that i(P, Q, H) and i(I - Q, I - P, H) are unitarily equivalent via a unitary operator in L(H). A counterexample is constructed, which shows that the same may be not true when (P, Q) fails to be semi-harmonious. Likewise, a counterexample is constructed such that (P, Q) is semi-harmonious, whereas (P, I - Q) is not semi-harmonious. Some additional examples indicating new phenomena of adjointable operators acting on Hilbert C*-modules are also provided. 相似文献
18.
The P 2-integral of James is compared with the T 2-integral. A trigonometric series convergent almost everywhere to a function which is T 2-integrable but not P 2-integrable is constructed. 相似文献
19.
In this paper, we construct representatives for all equivalence classes of the unital essential extension algebras of Cuntz algebra by the C*-algebras of compact operators on a separable infinite-dimensional Hilbert space. We also compute their K-groups and semigroups and classify these extension algebras up to isomorphism by their semigroups. 相似文献
20.
It is proved that a class of multilinear singular integral operators with homogeneous kernels are bounded operators from the
product spaces
to the Hardy spacesH
r
, (ℝ
n
) and the weak Hardy spaceH
r,∞ (ℝ
n
. As an application of this result, the L
p
,(ℝ
n
) boundedness of a class of commutator for the singular integral with homogeneous kernels is obtained.
Project supparted in part by the National Natural Science Foundation of Chind (Grant No. 19131080) of China and Doctoral Programme
Foundation of Institution of Higher Education (Grant No. 98002703) of China. 相似文献