Computational Methods and Function Theory 9 (2009), No. 2, 421--433
Copyright Heldermann Verlag 2009
Javad Mashreghi
javad.mashreghi@mat.ulaval.ca , Université Laval, Département de mathématiques et de statistique, Québec, QC, G1V 0A6, Canada.
Mahmood Shabankhah
mahmood.shabankhah.1@ulaval.ca , Université Laval, Département de mathématiques et de statistique, Québec, QC, G1V 0A6, Canada.
Let B be a Blaschke product for the open unit disc with zeros (zn)n > 1. We assume that Σn=1∞ h(1-|z_n|)<∞, where h is a given positive continuous functions. A typical example that has been extensively studied before is h(t) = tα, 0≤α≤1. Then we find upper bounds for the Hardy and Bergman means of the logarithmic derivative of B.
Keywords: Blaschke products, integral means, Hardy spaces, Bergman spaces.
MSC 2000: Primary 30D50, Secondary 26A12.
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