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A subclass of univalent functions

Published online by Cambridge University Press:  09 April 2009

R. M. Goel
Affiliation:
Department of Mathematics, Panjabi University, Patiala-147002, (Panjab State), India
Beant Singh Mehrok
Affiliation:
Department of Mathematics, Panjabi University, Patiala-147002, (Panjab State), India
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Abstract

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Sharp results for the cofficient estimates, distortion theorems, radius of convexity, arc-length and area of the image curve are obtained for the class R(A, B) of regular functions whose derivative is subordinate to (1+AZ)/(1+Bz), -1 ≤ BA ≤ 1, in the unit disc E = {z:|z| < 1}. We also establish a convolution theorem for this class.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1983

References

[1]Alexander, J. W., ‘Functions which map the interior of the unit circle upon simple regions’, Ann. of Math. 17 (1915), 1222.CrossRefGoogle Scholar
[2]Bernardi, S. D., ‘Special classes of subordinate functions’, Duke Math. J. 33 (1966), 5567.CrossRefGoogle Scholar
[3]Brickman, L., ‘Subordinate families of analytic functions’, Illinois J. Math. 15 (1971), 241248.CrossRefGoogle Scholar
[4]Capling, T. R. and Causey, W. M., ‘A class of univalent functions’, Proc. Amer. Math. Soc. 39 (1973), 357361.CrossRefGoogle Scholar
[5]Goel, R. M., ‘A class of univalent functions whose derivatives have positive real part in the unit disc’, Nieuw Arch. Wisk. (3), 15 (1967), 5563.Google Scholar
[6]Goel, R. M., ‘A class analytic functions whose derivatives have positive real part in the unit disc’, Indian J. Math. 3 (1971), 141145.Google Scholar
[7]Littlewood, J. E., ‘On inequalities in the theory of functions’, Proc. London Math. Soc. (2), 23 (1925), 481519.CrossRefGoogle Scholar
[8]Littlewood, J. E., Lectures on the theory of functions, pp. 163185 (Oxford Univ. Press, London, 1944).Google Scholar
[9]MacGregor, T. H., ‘Functions whose derivative has a positive real part’, Trans. Amer. Math. Soc. 104 (1962), 532537.CrossRefGoogle Scholar
[10]MacGregor, T. M., ‘A class of univalent functions’, Proc. Amer. Math. Soc. 15 (1964), 311317.CrossRefGoogle Scholar
[11]Nehari, Z., Conformal mapping (McGraw Hill, New York, 1952).Google Scholar
[12]Noshiro, K., ‘On the theory of schlicht functions’, J. Fac. Sci. Hokkaido Univ. (1), 2 (19341935), 129155.Google Scholar
[13]Padmanabhan, K. S., ‘On a certain class of functions whose derivatives have a positive real part in the unit disc’, Ann. Polon. Math. 23 (1970), 7381.CrossRefGoogle Scholar
[14]Robertson, M. S., ‘Quasi-subordinate functions’, Mathematical essays dedicated to A. J. MacIntyre, pp. 311330 (Ohio Univ. Press, Athens, Ohio, 1967).Google Scholar
[15]Singh, V. and Goel, R. M., ‘On radii of convexity and starlikeness of some classes of functions’, J. Math. Soc. Japan 23 (1971), 323339.CrossRefGoogle Scholar
[16]Warschawaki, S. S., ‘On the higher derivatives at the boundary in conformal mappings’, Trans. Amer. Math. Soc. 8 (1935), 310340.CrossRefGoogle Scholar
[17]Wolff, J., ‘L'intégrale d'une fonction holomorphe et à partie réelle positive dans un demiplan est univalente’, C. R. Acad. Sci. Paris Sér A-B 198 (1934), 12091210.Google Scholar