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Mostrando ítems 1-10 de 25
Artículo
Two weight extrapolation via the maximal operator
(Elsevier, 2000-06-20)
We give several extrapolation theorems for pairs of weights of the form (w, Mkw) and (w, (Mw/w)r w), where w is any non-negative function, r>1, and Mk is the kth iterate of the Hardy–Littlewood maximal operator. As an ...
Artículo
Banach spaces of hypercyclic vectors
(University of Michigan, 1996)
Artículo
Fixed points and approximate fixed points in product spaces
(The Mathematical Society of the Republic of China, 2001-06)
The paper deals with the general theme of what is known about the existence of fixed points and approximate fixed points for mappings which satisfy geometric conditions in product spaces. In particular it is shown that ...
Artículo
A geometrical coefficient implying the fixed point property and stability results
(University of Houston, 1996)
In this paper we define a new geometric constant M(X) in Banach spaces such that X has the fixed point property for nonexpansive mappings if M(X) > 1. We prove that M(X) •_ WCS(X), the inequality being strict in many ...
Artículo
Two-weight, weak-type norm inequalities for fractional integrals, Calderón-Zygmund operators and commutators
(Indiana University, 2000)
We give Ap-type conditions which are sufficient for the two-weight, weak-type (p, p) inequalities for fractional integral operators, Calderón-Zygmund operators and commutators. For fractional integral operators, this solves ...
Artículo
The fixed-point property in Banach spaces containing a copy of c0
(Hindawi, 2003)
We prove that every Banach space containing an isomorphic copy of c0 fails to have the fixed-point property for asymptotically nonexpansive mappings with respect to some locally convex topology which is coarser than the ...
Artículo
Sharp weighted inequalities for the vector-valued maximal function
(American Mathematical Society, 2000)
We prove in this paper some sharp weighted inequalities for the vector-valued maximal function Mq of Fefferman and Stein defined by Mqf(x) = X∞ i=1 (M fi(x))q !1/q, where M is the Hardy-Littlewood maximal function. As a ...
Artículo
Remarks on multivalued nonexpansive mappings
(Soochow University, 1995-01)
Convergence of fixed point sets of multivalued nonexpansive mappings is studied under both the Mosco and Hausdorff senses. A characterization for *- nonexpansive multivalued mappings is given. Also a counterexample is ...
Artículo
Artículo
Riesz's theorem for orthogonal matrix polynomials
(Springer, 1999-01)
We describe the image through the Stieltjes transform of the set of solutions V of a matrix moment problem. We extend Riesz's theorem to the matrix setting, proving that those matrices of measures of V for which the matrix ...