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Mostrando ítems 21-25 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
Concentration of the distance in finite dimensional normed spaces
(University College London, Faculty of Mathematical and Physical Sciences, Department of Mathematics, 1998-12)
We prove that in every finite dimensional normed space, for “most” pairs (x, y) of points in the unit ball, ∥x − y∥ is more than √2(1 − ε). As a consecuence, we obtain a result proved by Bourgain, using QS-descomposition, ...
Artículo
Endpoint estimates for commutators of singular integral operators
(Elsevier, 1995-02-15)
We prove endpoint estimates for commutatotrs of singular integrals with BMO functions. We first show that they satisfy L(log L) type inequalities and then that there is a Hardy space type estimate where the usual atomic ...
Artículo
Two-weight, weak-type norm inequalities for singular integral operators
(International Press, 1999)
We give a sufficient condition for singular integral operators and, more generally, Calder´on-Zygmund operators to satisfy the weak (p, p) inequality u({x ∈ R n : |T f(x)| > t}) ≤ C / tp Z Rn |f|p v dx, 1 < p < ∞. Our ...