We prove weighted inequalities for commutators of one-sided singular integrals (given by a Calderón-Zygmund kernel with support in (−∞, 0)) with BMO functions. We give the one-sided version of the results in [C. Pérez, Sharp estimates for commutators of singular integrals via iterations of the Hardy-Littlewood maximal function, J. Fourier Anal. Appl., vol. 3 (6), 1997, pages 743–756] and [C. Pé...

Abstract. We present a class of initial-configurations for the Cucker-Smale flocking type models leading no finite-time collisions between particles. For this class of initial-configurations, the global existence of smooth solutions to the Cucker-Smale model with singular communication weights is established. This also generalizes the earlier flocking estimates for the Cucker-Smale type models ...

We study compact embeddings for weighted spaces of Besov and TriebelLizorkin type where the weights belong to Muckenhoupt Ap classes. We focus our attention on the influence of singular points of the weights on the compactness of the embeddings as well as on the asymptotic behaviour of their entropy and approximation numbers.

The theory of (Muckenhoupt) weights arises in many areas of analysis, for example in connection with bounds for singular integrals and maximal functions on weighted spaces. We prove that a certain averaging process gives a method for constructing Ap weights from a measurably varying family of dyadic Ap weights. This averaging process is suggested by the relationship between the Ap weight class ...

where Ω is an open bounded set of R and W and V are two non-negative continuous functions vanishing at α, β and α, β, respectively. In the previous functional, we fix a = 2 − p and u is a scalar density function, Tu denotes its trace on ∂Ω, d(x, ∂Ω) stands for the distance function to the boundary ∂Ω. We show that the singular limit of the energies Fε leads to a coupled problem of bulk and surf...

The null vectors of an arbitrary highest weight representation of the WA2 algebra are constructed. Using an extension of the enveloping algebra by allowing complex powers of one of the generators, analysed by Kent for the Virasoro theory, we generate all the singular vectors indicated by the Kac determinant. We prove that the singular vectors with given weights are unique up to normalisation an...