On the logarithmic coefficients of close to convex functions (Q2790274)

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scientific article; zbMATH DE number 6549233
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On the logarithmic coefficients of close to convex functions
scientific article; zbMATH DE number 6549233

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    On the logarithmic coefficients of close to convex functions (English)
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    3 March 2016
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    close to convex functions
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    logarithmic coefficients
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    For a normalized analytic function \(f\), define the logarithmic coefficients \(\gamma_n\) by NEWLINENEWLINE\[NEWLINE\log\frac{f(z)}{z} = 2\sum_{n=1}^{\infty}\gamma_nz^n.NEWLINE\]NEWLINE Let \(f\) be analytic and close to convex in the unit disk \(\mathbb D\). This means that there exists a star-like function \(g\) such that NEWLINE\[NEWLINE\mathrm{Re} \frac{zf'(z)}{g(z)} > 0, \quad z \in \mathbb D.NEWLINE\]NEWLINE The author obtains sharp estimates for the logarithmic coefficients \(\gamma_1, \gamma_2, \gamma_3\) of close to convex functions.
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