Counterexamples to some pointwise estimates of the maximal Cauchy transform in terms of the Cauchy transform

Motivated by the work of Mateu, Orobitg, Pérez and Verdera, who proved inequalities of the form T _*f\lesssim M(Tf) or T _*f\lesssim M^2(Tf) for certain singular integral operators T, such as the Hilbert or the Beurling transforms, we study the possibility of establishing this type of control for th...

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Bibliographic Details
Author: Girela Sarrión, Daniel
Format: master thesis
Publication Date:2012
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:102070
Online Access:https://ddd.uab.cat/record/102070
Access Level:Open access
Keyword:Cauchy, Transformació de
Operadors, Teoria dels
Desigualtats (Matemàtica)
Grafs, Teoria dels
Description
Summary:Motivated by the work of Mateu, Orobitg, Pérez and Verdera, who proved inequalities of the form T _*f\lesssim M(Tf) or T _*f\lesssim M^2(Tf) for certain singular integral operators T, such as the Hilbert or the Beurling transforms, we study the possibility of establishing this type of control for the Cauchy transform along a Lipschitz graph. We show that this is not possible in general, and we give a partial positive result when the graph is substituted by a Jordan curve.