On a powered Bohr inequality

By Ilgiz R. Kayumov, Saminathan Ponnusamy. Annales Academiae Scientiarum Fennicae: Mathematica, 2018

92 citations recorded by the source corpus.

The object of this paper is to study the powered Bohr radius $\rho_p$, $p \in (1,2)$, of analytic functions $f(z)=\sum_{k=0}^{\infty} a_kz^k$ and such that $|f(z)|<1$ defined on the unit disk $|z|<1$. More precisely, if $M_p^f (r)=\sum_{k=0}^\infty |a_k|^p r^k$, then we show that $M_p^f (r)\leq 1$ for $r \leq r_p$ where $r_\rho$ is the powered Bohr radius for conformal automorphisms of the unit disk. This answers the open problem posed by Djakov and Ramanujan in 2000. A couple of other consequences of our approach is also stated, including an asymptotically sharp form of one of the results of Djakov and Ramanujan. In addition, we consider a similar problem for sense-preserving harmonic mappings in $|z|<1$. Finally, we conclude by stating the Bohr radius for the class of Bieberbach-Eilenberg functions.

Subfields: Algebra and Number Theory, Geometry and Topology

View Paper: https://www.semanticscholar.org/paper/6c852c9bb76f257a1d58678e3a0f97bc8208fdeb

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Algebra and Number Theory

  1. V. Allu
  2. H. Halder
  3. Saminathan Ponnusamy

In Geometry and Topology

  1. V. Allu
  2. H. Halder
  3. Saminathan Ponnusamy
  4. Ilgiz R. Kayumov
  5. A. Ismagilov
  6. 'Arp'ad Baricz

Citations in the corpus