A multiplier theorem for ultraspherical series
Let be a nonnegative Radon measure on which only satisfies for all , , with some fixed constants and In this paper, a new characterization for the space of Tolsa in terms of the John-Strömberg sharp maximal function is established.
Distributional estimates for the Carleson operator acting on characteristic functions of measurable sets of finite measure were obtained by Hunt. In this article we describe a simple method that yields such estimates for general operators acting on one or more functions. As an application we discuss how distributional estimates are obtained for the linear and bilinear Hilbert transform. These distributional estimates show that the square root of the bilinear Hilbert transform is exponentially lntegrable...
We give a new and simpler proof of a two-weight, weak inequality for fractional integrals first proved by Cruz-Uribe and Pérez [4].
We study the regularity of refinable functions by analyzing the spectral properties of special operators associated to the refinement equation; in particular, we use the Fredholm determinant theory to derive numerical estimates for the spectral radius of these operators in certain spaces. This new technique is particularly useful for estimating the regularity in the cases where the refinement equation has an infinite number of nonzero coefficients and in the multidimensional cases.