3 research outputs found
Univalence criteria for general integral operator
Let be the class of all analytic functions which are analytic
in the open unit disc and
[
G_{b}=left{ fin mathcal{A}:leftvert frac{%
1+zf^{prime prime }(z)/f^{prime }(z)}{zf^{prime }(z)/f(z)}-1rightvert
<b, zin mathcal{U}right} .
]
In this paper, we derive sufficient
conditions for the integral operator
[
I_{gamma }^{alpha _{i} }(f_{1},...,f_{n})(z)=left{ gamma
intlimits_{0}^{z}t^{gamma -1}left( f_{1}^{prime }(t)right) ^{alpha
_{1}}left( frac{f_{1}(t)}{t}right) ^{1-alpha _{1}}...left(
f_{n}^{prime }(t)right) ^{alpha _{n}}left( frac{f_{n}(t)}{t}right)
^{1-alpha _{n}}dtright} ^{frac{1}{gamma }}
]
to be analytic and
univalent in the open unit disc, when for
all $i=1,ldots ,n.
On General Integral Operator of Analytic Functions
Let be the integral operator defined by , where each of the functions and is, respectively, analytic functions and functions
with positive real part defined in the open unit disk for all . The object of
this paper is to obtain several univalence conditions for this integral operator. Our main
results contain some interesting corollaries as special cases