共查询到20条相似文献,搜索用时 9 毫秒
1.
Chunjie Wang 《Journal of Mathematical Analysis and Applications》2011,373(2):393-398
Let Ap(D) (1?p<∞) be the Bergman space over the open unit disk D in the complex plane. For p?1, let cp be the largest value of c for which Korenblum's maximum principle holds. In this paper we obtain a new lower bound on cp: cp?0.23917. We also improve the lower bound on c2 up to 0.28185. 相似文献
2.
Chunjie Wang 《Proceedings of the American Mathematical Society》2006,134(7):2061-2066
Let be the Bergman space over the open unit disk in the complex plane. Korenblum's maximum principle states that there is an absolute constant , such that whenever ( ) in the annulus , then . In this paper we prove that Korenblum's maximum principle holds with .
3.
Chunije Wang 《Mathematische Nachrichten》2008,281(3):447-454
Let Ap (??) (p ≥ 1) be the Bergman space over the open unit disk ?? in the complex plane. Korenblum's maximum principle states that there is an absolute constant c ∈ (0, 1) (may depend on p), such that whenever |f (z)| ≤ |g (z)| (f, g ∈ Ap (??)) in the annulus c < |z | < 1, then ∥f ≤ ∥g ∥. For p ≥ 1, let cp be the largest value of c for which Korenblum's maximum principle holds. In this note we prove that cp → 1 as p → ∞. Thus we give a positive answer of a question of Hinkkanen. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
4.
5.
Anna Betiuk-Pilarska 《Journal of Mathematical Analysis and Applications》2011,382(1):127-131
Estimates for the James constant for various norms in real interpolation spaces for finite families of Banach spaces are given. As a corollary it is shown that if a family contains at least one space which is uniformly nonsquare, then the interpolation space is uniformly nonsquare. 相似文献
6.
A note on Jordan-von Neumann constant and James constant 总被引:2,自引:0,他引:2
Changsen Yang 《Journal of Mathematical Analysis and Applications》2009,357(1):98-102
Let X be a non-trivial Banach space. L. Maligranda conjectured CNJ(X)?1+J2(X)/4 for James constant J(X) and von Neumann-Jordan constant CNJ(X) of X. Satit Saejung gave a proof of it in 2006. In this note, we show that the last step in Satit Saejung's proof is not valid. Using his proof, the result should be . On the other hand, we give a new proof of CNJ(X)?1+J2(X)/4. As an application, we give a relation between J(X) and J(lp(X)). 相似文献
7.
In this paper, we give a characterization of best constant approximants in Lorentz spaces Lw,q, 1q<∞, and we establish a way to obtain the best constant approximants maximum and minimum. We also study monotony of the best constant approximation operator. 相似文献
8.
In this paper,we prove that the original Littlewood-Paley g-functions can be used to characterize Bergman spaces as well. 相似文献
9.
We introduce a generalized James constant J(a,X) for a Banach space X, and prove that, if J(a,X)<(3+a)/2 for some a∈[0,1], then X has uniform normal structure. The class of spaces X with J(1,X)<2 is proved to contain all u-spaces and their generalizations. For the James constant J(X) itself, we show that X has uniform normal structure provided that , improving the previous known upper bound at 3/2. Finally, we establish the stability of uniform normal structure of Banach spaces. 相似文献
10.
Piotr Jakóbczak 《Rendiconti del Circolo Matematico di Palermo》2008,57(2):255-263
In this note we study the behaviour of holomorphic functions from the Bergman and Fock spaces on the rays of the unit disc
U and the complex plane ℂ. We obtain conditions on the finiteness of weighted L
2-integrals of those functions along rays.
相似文献
11.
12.
E.G. Kwon 《Journal of Mathematical Analysis and Applications》2008,338(2):758-770
Let 0?α<∞, 0<p<∞, and p−α>−2. If f is holomorphic in the unit disc D and if ω is a radial weight function of secure type, then the followings are equivalent:
13.
14.
In this paper we study complete orientable surfaces with a constant principal curvature R in the 3‐dimensional hyperbolic space H 3. We prove that if R2 > 1, such a surface is totally umbilical or umbilically free and it can be described in terms of a complete regular curve in H 3. When R2 ≤ 1, we show that this result is not true any more by means of several examples. This contradicts a previous statement by Zhisheng [6]. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
Ken-Ichi Mitani Tomonari Suzuki 《Journal of Mathematical Analysis and Applications》2008,343(1):310-314
In [M. Kato, L. Maligranda, On James and Jordan-von Neumann constants of Lorentz sequence spaces, J. Math. Anal. Appl. 258 (2001) 457-465], the James constant of the 2-dimensional Lorentz sequence space d(2)(ω,q) is computed in the case where 2?q<∞. It is an open problem to compute it in the case where 1?q<2. In this paper, we completely determine the James constant of d(2)(ω,q) in the case where 1?q<2. 相似文献
16.
In the article, we derive an explicit formula for the double exponential map on spaces of constant curvature. In addition, we consider some applications of the resulting formula to computing the principal symbol of the product of two pseudodifferential operators on a manifold with connection. 相似文献
17.
In this paper,by lifting the Bergman shift as the compression of an isometry on a subspace of the Hardy space of the bidisk,we give a proof of the Beurling type theorem on the Bergman space of Aleman,Richter and Sundberg(1996) via the Hardy space of the bidisk. 相似文献
18.
This paper gives the compactness criteria for a kind of generalized Hankel operators on Bergman spaces Lpa(B) defined by M.M.Peloso. 相似文献
19.
本文研究了Bergman空间上的复合算子的范数与再生核的关系,证明了紧复合算子C的范数‖C‖=sup{‖C*kw‖:w∈D}的充要条件是(0)=0或是仿射映射,即(z)=sz+t,s,t是满足|s|+|t|<1的常数,其中kw为Bergman空间的规范再生核, C*是C的共轭算子. 相似文献
20.
Lu YU-FENG YANG JUN 《东北数学》2009,25(2):159-164
In this paper we concern with the characterization of bounded linear operators S acting on the weighted Bergman spaces on the unit ball. It is shown that, if S satisfies the commutation relation STzi = Tzi(i =1,..,n), where Tzi = zif and Tzi= P(zif) where P is the weighted Bergman projection, then S must be a Hankel operator. 相似文献