BOUNDS FOR RADII OF CONVEXITY OF SOME q-BESSEL FUNCTIONS

Aktas I., ORHAN H.

BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, vol.57, no.2, pp.355-369, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 2
  • Publication Date: 2020
  • Doi Number: 10.4134/bkms.b190242
  • Journal Name: BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, MathSciNet, zbMATH
  • Page Numbers: pp.355-369
  • Keywords: Convex functions, radius of convexity, Mittag-Leffler expansions, q-Bessel functions, zeros of q-Bessel functions, Laguerre-Polya class of entire functions, GEOMETRIC-PROPERTIES, STARLIKENESS, ZEROS, LOMMEL
  • Ataturk University Affiliated: Yes

Abstract

In the present investigation, by applying two different normalizations of the Jackson's second and third q-Bessel functions tight lower and upper bounds for the radii of convexity of the same functions are obtained. In addition, it was shown that these radii obtained are solutions of some transcendental equations. The known Euler-Rayleigh inequalities are intensively used in the proof of main results. Also, the Laguerre-Polya class of real entire functions plays an important role in this work.