Geometric Properties of function $az^{2}J_{\nu }^{\prime \prime }(z)+bzJ_{\nu }^{\prime}(z)+cJ_{\nu }(z)$

Abstract

In this paper our aim is to find the radii of starlikeness and convexity for three different kind of normalization of the $N_\nu(z)=az^{2}J_{\nu }^{\prime \prime }(z)+bzJ_{\nu }^{\prime}(z)+cJ_{\nu }(z)$ function, where $J_\nu(z)$ is called the Bessel function of the first kind of order $\nu.$ The key tools in the proof of our main results are the Mittag-Leffler expansion for $N_\nu(z)$ function and properties of real zeros of it. In addition, by using the Euler-Rayleigh inequalities we obtain some tight lower and upper bounds for the radii of starlikeness and convexity of order zero for the normalized $N_\nu(z)$ function. Finally, we evaluate certain multiple sums of the zeros for $N_\nu(z)$ function.