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Sharp starlikeness conditions for analytic functions with bounded derivative

Published online by Cambridge University Press:  09 April 2009

Frode Rønning
Affiliation:
Sør Trøndelag College School of Teacher EducationN-7004 TrondheimNorway e-mail: [email protected]
Stephan Ruscheweyh
Affiliation:
Mathematisches Institut Universität WürzburgD-97074 WürzburgGermany e-mail: [email protected]
Nikolas Samaris
Affiliation:
Department of Mathematics University of PatrasGR-26500 PatrasGreece e-mail: [email protected]
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Abstract

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We develop sharp conditions for various types of starlikeness for functions analytic in the unit disk with bounded derivatives. We also describe the precise range {zf′(z)/f(z): z ∈ D, f}, where f means f (0) = 0, f′(0) = 1, and |f′(z) - 1 |< ≦ λ in the unit disc D, and draw some cnoslusions from that.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2000

References

[1]Fournier, R., ‘On integrals of bounded analytic functions in the unit disk’, Complex Variables 11 (1989), 125133.Google Scholar
[2]Fournier, R., ‘The range of a continuous linear functional over a class of functions defined by subordination’, Glasgow Math. J. 32 (1990), 381387.CrossRefGoogle Scholar
[3]Goodman, A. W., ‘On uniformly starlike functions’, J. Math. Anal. Appl. 155 (1991), 364370.CrossRefGoogle Scholar
[4]Mocanu, P. T., ‘Some starlikeness conditions for analytic functions’, Rev. Roumaine Math. Pures Appl. 33 (1988), 117124.Google Scholar
[5]Ponnusamy, S. and Singh, V., ‘Criteria for strongly starlike functions’, Complex Variables 34 (1997), 267291.Google Scholar
[6]Rønning, F., ‘On uniform starlikeness and related properties of univalent functions’, Complex Variables 24 (1994), 233239.Google Scholar
[7]Rønning, F., ‘Uniformly convex functions and a corresponding class of starlike functions’, Proc. Amer. Math. Soc. 118 (1993), 189196.CrossRefGoogle Scholar
[8]Ruscheweyh, S., ‘Sharp conditions for starlikeness of analytic and meromorphic functions’, Mathematica, to appear.Google Scholar
[9]Samaris, N., ‘Differential inequalities and starlike functions’, preprint.Google Scholar
[10]Singh, V., ‘Univalent functions with bounded derivative in the unit disk’, Indian J. Pure Appl. Math. 8 (1977), 13701377.Google Scholar