Subordination criteria for starlikeness and convexity

Rasoul Aghalary, Jay M. Jahangiri
2003 International Journal of Mathematics and Mathematical Sciences  
For functionspanalytic in the open unit discU={z:|z|<1}with the normalizationp(0)=1, we consider the families𝒫[A,−1],−1<A≤1, consisting ofpsuch thatp(z)is subordinate to(1+Az)/(1−z)inUand𝒫(1,b),b>0, consisting ofp, which have the disc formulation|p−1|<binU. We then introduce subordination criteria for the choice ofp(z)=zf′(z)/f(z), wherefis analytic inUand normalized byf(0)=f′(0)−1=0. We also obtain starlikeness and convexity conditions for such functionsfand consequently extend and, in some
more » ... es, improve the corresponding previously known results.
doi:10.1155/s0161171203207146 fatcat:k4hkiwaen5ernnabot3ttugq7u