Starlikeness of the generalized integral transform using duality techniques

For $α\geq 0$, $δ>0$, $β<1$ and $γ\geq 0$, the class $\mathcal{W}_β^δ(α,γ)$ consist of analytic and normalized functions $f$ along with the condition \begin{align*} {\rm Re\,} e^{iϕ}(\dfrac{}{}(1\!-\!α\!+\!2γ)\!({f}/{z})^δ+(α\!-\!3γ\!+\!γ[\dfrac{}{}(1-{1}/δ)({zf'}/{f})+ {1}/δ(1+{zf''}/{f'})]).\\ .\dfrac{}{}({f}/{z})^δ\!({zf'}/{f})-β)>0, \end{align*} where $ϕ\in\mathbb{R}$ and $|z|<1$, is taken into consideration. The class $\mathcal{S}^\ast_s(ζ)$ be the subclass of the univalent functions, defined by the analytic characterization ${\rm Re}{\,}({zf'}/{f})>ζ$, for $0\leq ζ< 1$, $0<δ\leq\frac{1}{(1-ζ)}$ and $|z|<1$. The admissible and sufficient conditions on $λ(t)$ are examined, so that the generalized and non-linear integral transforms \begin{align*} V_λ^δ(f)(z)= (\int_0^1 λ(t) ({f(tz)}/{t})^δdt)^{1/δ}, \end{align*} maps the function from $\mathcal{W}_β^δ(α,γ)$ into $\mathcal{S}^\ast_s(ζ)$. Moreover, several interesting applications for specific choices of $λ(t)$ are discussed, that are related to some well-known integral operators.

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