English

Lp mean estimates for an operator preserving inequalities between polynomials

Complex Variables 2013-06-05 v1

Abstract

If P(z)P(z) be a polynomial of degree at most nn which does not vanish in z<1|z| < 1, it was recently formulated by Shah and Liman \cite[\textit{Integral estimates for the family of BB-operators, Operators and Matrices,} \textbf{5}(2011), 79 - 87]{wl} that for every R1R\geq 1, p1p\geq 1, B[Pσ](z)pRnΛn+λ01+zpP(z)p,\left\|B[P\circ\sigma](z)\right\|_p \leq\frac{R^{n}|\Lambda_n|+|\lambda_{0}|}{\left\|1+z\right\|_p}\left\|P(z)\right\|_p, where BB is a Bn \mathcal{B}_{n}-operator with parameters λ0,λ1,λ2\lambda_{0}, \lambda_{1}, \lambda_{2} in the sense of Rahman \cite{qir}, σ(z)=Rz\sigma(z)=Rz and Λn=λ0+λ1n22+λ2n3(n1)8\Lambda_n=\lambda_{0}+\lambda_{1}\frac{n^{2}}{2} +\lambda_{2}\frac{n^{3}(n-1)}{8}. Unfortunately the proof of this result is not correct. In this paper, we present a more general sharp LpL_p-inequalities for Bn\mathcal{B}_{n}-operators which not only provide a correct proof of the above inequality as a special case but also extend them for 0p<1 0 \leq p <1 as well.

Keywords

Cite

@article{arxiv.1306.0714,
  title  = {Lp mean estimates for an operator preserving inequalities between polynomials},
  author = {N. A. Rather and Suhail Gulzar},
  journal= {arXiv preprint arXiv:1306.0714},
  year   = {2013}
}

Comments

16 Pages

R2 v1 2026-06-22T00:27:39.764Z