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Mostrando ítems 11-20 de 24
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
Ap weights for nondoubling measures in Rn and applications
(American Mathematical Society, 2002)
We study an analogue of the classical theory of Ap(µ) weights in Rn without assuming that the underlying measure µ is doubling. Then, we obtain weighted norm inequalities for the (centered) Hardy-Littlewood maximal function ...
Artículo
Sharp weighted estimates for multilinear commutators
(London Mathematical Society, 2002-06)
Multilinear commutators with vector symbol Formula=(b1,…,bm) defined by Formula are considered, where K is a Calderón–Zygmund kernel. The following a priori estimates are proved for w ∈ A∞. For 0 < p < ∞, there exists ...
Artículo
Weak type estimates for singular integrals related to a dual problem of Muckenhoupt-Wheeden
(Springer, 2009-06)
A well known open problem of Muckenhoupt-Wheeden says that any Calderón-Zygmund singular integral operator T is of weak type (1, 1) with respect to a couple of weights (w, Mw). In this paper we consider a somewhat “dual” ...
Artículo
A new characterization of the Muckenhoupt Ap weights through an extension of the Lorentz-Shimogaki theorem
(Indiana University, 2007)
Given any quasi-Banach function space X over Rn it is defined an index αX that coincides with the upper Boyd index αX when the space X is rearrangement-invariant. This new index is defined by means of the local maximal ...
Artículo
New maximal functions and multiple weights for the multilinear Calderón-Zygmund theory
(Elsevier, 2009-03-01)
A multi(sub)linear maximal operator that acts on the product of m Lebesgue spaces and is smaller that the m-fold product of the Hardy-Littlewood maximal function is studied. The operator is used to obtain a precise control ...
Artículo
A1 bounds for Calderón-Zygmund operators related to a problem of Muckenhoupt and Wheeden
(International Press, 2009)
We obtain an Lp(w) bound for Calderón-Zygmund operators T when w ∈ A1. This bound is sharp both with respect to ∥w∥A1 and with respect to p. As a result, we get a new L1,∞(w) estimate for T related to a problem of Muckenhoupt ...
Artículo
L1 → Lq Poincaré inequalities for 0 < q < 1 imply representation formulas
(Springer, 2002-01)
Given two doubling measures μ and ν in a metric space (S, ρ) of homogeneous type, let B0⊂S be a given ball. It has been a well-known result by now (see [1–4]) that the validity of an L1→L1 Poincaré inequality of the following ...
Artículo
Sharp two-weight inequalities for singular integrals, with applications to the Hilbert transform and the Sarason conjecture
(Elsevier, 2007-12-20)
We prove two-weight norm inequalities for Calderón-Zygmund singular integrals that are sharp for the Hilbert transform and for the Riesz transforms. In addition, we give results for the dyadic square function and for ...
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 ...