Subclasses of uniformly starlike and convex functions defined by certain integral operator (Q882692)
From MaRDI portal
| This is the item page for this Wikibase entity, intended for internal use and editing purposes. Please use this page instead for the normal view: Subclasses of uniformly starlike and convex functions defined by certain integral operator |
scientific article; zbMATH DE number 5156824
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | Subclasses of uniformly starlike and convex functions defined by certain integral operator |
scientific article; zbMATH DE number 5156824 |
Statements
Subclasses of uniformly starlike and convex functions defined by certain integral operator (English)
0 references
24 May 2007
0 references
Two function classes \({\mathcal T}Q(\alpha ,\beta ,\lambda )\) and \({\mathcal T}{\mathcal J}(\alpha ,\sigma )\) are introduced by defining these classes, respectively, in terms of the functions \(F(z) = Q_\beta ^\alpha f(z)\) and \(F(z) = J_\alpha f(z),\) involving certain integral operators and satisfying the inequality: \[ \left| {\frac{{z\left( {F(Z)} \right)^\prime }}{{F(Z)}} - 1} \right| \leq \text{Re} \left\{ {\frac{{z\left( {F(Z)} \right)^\prime }}{{F(Z)}}} \right\} - \sigma \quad (z \in D), \] where \(\alpha>0, \beta>-1\: \text{and} \: 0\leq\sigma\leq1,\) D is the open unit disk, and \( f(z) = z - \sum_{n = 2}^\infty {a_n z^n }.\) The coefficient inequalities for the function \(f(z)\) belonging to the above classes (which are of uniformly starlike type) are obtained, and also similar investigations are undertaken for the functions which are of uniformly convex type.
0 references
analytic and univalent functions
0 references
integral operator
0 references
uniformly starlike functions
0 references
uniformly convex functions
0 references