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Artículo
Strongly compact algebras
(Real Academia de Ciencias Exactas, Fisicas y Naturales, 2006)
An algebra of bounded linear operators on a Hilbert space is said to be strongly compact if its unit ball is relatively compact in the strong operator topology. A bounded linear operator on a Hilbert space is said to be ...
Artículo
Structure of the fixed point set and common fixed points of asymptotically nonexpansive mappings
(American Mathematical Society, 2001)
Let X be a Banach space, C a weakly compact convex subset of X and T : C → C an asymptotically nonexpansive mapping. Under the usual assumptions on X which assure the existence of fixed point for T, we prove that the set ...
Artículo
Potential operators, maximal functions, and generalizations of A∞
(Springer, 2003-08)
We derive weighted norm estimates which relate integral operators of potential type (fractional integrals) to corresponding maximal operators (fractional maximal operators). We also derive norm estimates for the maximal ...
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
Uniformly Lipschitzian mappings in modular function spaces
(Elsevier, 2001-10)
Let ρ be a convex modular function satisfying a ∆2-type condition and Lρ the corresponding modular space. Assume that C is a ρ-bounded and ρ-a.e compact subset of Lρ and T : C → C is a k-uniformly Lipschitzian mapping. ...
Artículo
Asymptotically nonexpansive mappings in modular function spaces
(Elsevier, 2002-01-15)
In this paper, we prove that if ρ is a convex, σ-finite modular function satisfying a ∆2-type condition, C a convex, ρ-bounded, ρ-a.e. compact subset of Lρ and T : C → C a ρ-asymptotically nonexpansive mapping, then T has ...
Artículo
Uncertainty principle estimates for vector fields
(Elsevier, 2001-04-01)
We derive weighted norm estimates for integral operators of potential type and for their related maximal operators. These operators are generalizations of the classical fractional integrals and fractional maximal functions. ...
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
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
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 ...