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Estimates for Convex Integral Means of Harmonic Functions

Published online by Cambridge University Press:  22 November 2013

Dimitrios Betsakos
Dimitrios Betsakos*
Affiliation:
Department of Mathematics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece, (betsakos@math.auth.gr)
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Abstract

We prove that if f is an integrable function on the unit sphere S in ℝn, g is its symmetric decreasing rearrangement and u, v are the harmonic extensions of f, g in the unit ball , then v has larger convex integral means over each sphere rS, 0 < r < 1, than u has. We also prove that if u is harmonic in with |u| < 1 and u(0) = 0, then the convex integral mean of u on each sphere rS is dominated by that of U, which is the harmonic function with boundary values 1 on the right hemisphere and −1 on the left one.

Keywords

harmonic functionintegral meanssymmetric decreasing rearrangementharmonic measurepolarizationSchwarz lemmaPrimary 31B0531B15
Type
Research Article
Information
Proceedings of the Edinburgh Mathematical Society , Volume 57 , Issue 3 , October 2014 , pp. 619 - 630
Copyright
Copyright © Edinburgh Mathematical Society 2014 

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