On the differentiability of T(r,f)
It is well known that T(r,f) is differentiable at least for r>r0. We show that, in fact, T(r,f) is differentiable for all but at most one value of r, and if T(r,f) fails to have a derivative for some value of r, then f is a constant times a quotient of finite Blaschke products.
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Format: | Article |
Language: | English |
Published: |
Hindawi Limited
1982-01-01
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Series: | International Journal of Mathematics and Mathematical Sciences |
Subjects: | |
Online Access: | http://dx.doi.org/10.1155/S0161171282000337 |