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Subclasses of Starlike Functions Subordinate to Convex Functions

Published online by Cambridge University Press:  20 November 2018

H. Silverman
Affiliation:
College of Charleston, Charleston, South Carolina
E. M. Silvia
Affiliation:
University of California, Davis, Davis, California
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Let S denote the class of functions of the form

that are analytic and univalent in the unit disk Δ = {z:|z| < 1}, with S*(α) and K(α) designating the subclasses of S that are, respectively, starlike of order a and convex of order α, 0 ≦ α < 1. If f(z) and g(z) are analytic in Δ, we say that f(z) is subordinate to g(z), written fg, if there exists a Schwarz function w(z), w(0) = 0 and |w(z)| < 1 in Δ, such that f(z) = g(w(z)). A function f(z) = z + … is said to be in S*[A, B] if

(1)

and in K[A, B] if

(2)

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1985

References

1. Eenigenburg, P., Miller, S. S., Mocanu, P. T. and Reade, M. O., On a Briot-Bouquet differential subordination, Rev. Roum. Math. Pures et Appl., to appear.CrossRefGoogle Scholar
2. Goel, R. M. and Mehrok, B. S., On the coefficients of a subclass of starlike functions, Indian J. Pure and Applied Math. 12 (1981), 634647.Google Scholar
3. Goel, R. M. and Mehrok, B. S., Some invariance properties of a subclass of close-to-convex functions, Indian J. Pure and Applied Math. 12 (1981), 12401249.Google Scholar
4. Goluzin, G. M., Geometric theory of functions of a complex variable, Translations of Mathematical Monographs (American Mathematical Society, Providence, Rhode Island, 1969).CrossRefGoogle Scholar
5. Janowski, W., Some extremal problems for certain families of analytic functions, Bull, de L'Acad. Pol. des Sci. 21 (1973), 1725.Google Scholar
6. Libera, R. J., Some classes of regular univalent functions, Proc. Amer. Math. Soc. 16 (1965), 755758.Google Scholar
7. MacGregor, T. H., A subordination for convex functions of order α, J. London Math. Soc. (2), 9 (1975), 530536.Google Scholar
8. Ruscheweyh, St., New criteria for univalent functions, Proc. Amer. Math. Soc. 49 (1975), 109115.Google Scholar
9. Ruscheweyh, St. and Sheil-Small, T., Hadamard products of schlicht functions and the Pólya-Schoenberg conjecture, Comment, Math. Helv. 48 (1973), 119135.Google Scholar
10. Silverman, H., Subclasses of starlike functions, Rev. Roum. Math. Pures et Appl. 23 (1978), 10931099.Google Scholar
11. Silverman, H., Silvia, E. M. and Telage, D. N., Convolution conditions for convexity, starlikeness and spiral-likeness, Math. Z. 162 (1978), 125130.Google Scholar