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Meromorphic univalent functions with positive coefficients

Published online by Cambridge University Press:  17 April 2009

M.L. Mogra
Affiliation:
School of Mathematical Sciences, University of Khartoum, Khartoum, SUDAN.
T.R. Reddy
Affiliation:
Department of Mathematics, Indian Institute of Technology, Kanpur-208016, INDIA.
O.P. Juneja
Affiliation:
Department of Mathematics, Kakatiya University, Warangal-506009, AP, INDIA.
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Abstract

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For the class of meromorphically starlike functions of prescribed order, the concept of type has been introduced. A characterization of meromorphically starlike functions of order α and type β has been obtained when the coefficients in its Laurent series expansion about the origin are all positive. This leads to a study of coefficient estimates, distortion theorems, radius of convexity estimates, integral operators, convolution properties et cetera for this class. It is seen that the class considered demonstrates, in some respects, properties analogous to those possessed by the corresponding class of univalent analytic functions with negative coefficients.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1985

References

[1]Bajpai, S.K., “A note on a class of meromorphic univalent functions”, Rev. Roumanie Math. Pures Appl. 22 (1977), 295297.Google Scholar
[2]Clunie, J., “On meromorphic schlicht functions”, J. London Math. Soc. 34 (1959), 215216.Google Scholar
[3]Goel, R.M. and Sohi, N.S., “On a class of meromorphic functions”, Glasnik Matematicki 17 (1981), 1928.Google Scholar
[4]Gupta, V.P. and Jain, P.K., “Certain classes of univalent functions with negative coefficients”, Bull. Austral. Math. Soc. 14 (1976), 409416.Google Scholar
[5]Juneja, O.P. and Mogra, M.L., “On starlike functions of order α and type β”, Notices Amer. Math Soc. 22 (1975), A-384; Abstract No. 75T-B80.Google Scholar
[6]Juneja, O.P. and Mogra, M.L., “On starlike functions of order a and type β”, Rev. Rownaine Math. Puree Appl. 23 (1978), 751765.Google Scholar
[7]Juneja, O.P. and Reddy, T.R., “Meromorphic starlike univalent functions with positive coefficients” (communicated).Google Scholar
[8]Miller, J.E., “Convex meromorphic mappings and related functions”, Proc. Amer. Math. Soc. 25 (1970), 220228.Google Scholar
[9]Mogra, M.L. and Juneja, O.P., “Coefficient estimates for starlike functions”, Bull. Austral. Math. Soc. 16 (1977), 415425.Google Scholar
[10]Padmanabhan, K.S., “On certain classes of starlike functions in the unit disc”, J. Indian Math. Soc. (N.s) 32 (1968), 89103.Google Scholar
[11]Pommerenke, Ch., “On meromorphic starlike functions”, Pacific J. Math. 13 (1963), 221235.CrossRefGoogle Scholar
[12]Robertson, M.S., “Convolutions of schlicht functions”, Proc. Amer. Math. Soc. 13 (1962), 585589.Google Scholar
[13]Royster, W.C., “Meromorphic starlike multivalent functions”, Trans. Amer. Math. Soc. 107 (1963), 300308.CrossRefGoogle Scholar
[14]Schild, A. and Silverman, H., “Convolution of univalent functions with negative coefficients”, Ann. Univ. Mariae. Curie. Sklodwska Sect. A29 (1975), 99107.Google Scholar
[15]Silverman, H., “Univalent functions with negative coefficients”, Proc. Amer. Math. Soc. 51 (1975), 109116.CrossRefGoogle Scholar
[16]Silverman, H., “Extreme points of univalent functions with two fixed points”, Trans. Amer. Math. Soc. 219 (1976), 387395.CrossRefGoogle Scholar
[17]Silverman, H. and Silvia, E.M., “Prestarlike functions with negative coefficients”, Internat. J. Math. and Math. Sci. 2 (1979), 427439.CrossRefGoogle Scholar