Buscar
Mostrando ítems 1-10 de 24
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
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
Extrapolation from A∞ weights and applications
(Elsevier, 2004-08-15)
We generalize the Ap extrapolation theorem of Rubio de Francia to A∞ weights in the context of Muckenhoupt bases. Our result has several important features. First, it can be used to prove weak endpoint inequalities starting ...
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
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
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 ...
Artículo
Maximal functions and the control of weighted inequalities for the fractional integral operator
(Indiana University, 2005)
We study weak-type (1, 1) weighted inequalities for the fractional integral operator Iα. We show that the fractional maximal operator Mα controls these inequalities when the weight is radially decreasing. However, we exhibit ...
Artículo
A sum operator with applications to self-improving properties of Poincaré inequalities in metric spaces
(Springer, 2003-09)
We define a class of summation operators with applications to the self-improving nature of Poincaré-Sobolev estimates, in fairly general quasimetric spaces of homogeneous type. We show that these sum operators play the ...