Abstract
In this paper the sharp coefficient estimate problem for the classesC p(β, m) andV p(k,m) of multivalent close-to-convex functions of order β and multivalent functions of bounded boundary rotation of at mostkπ, whose functions are given bym-fold symmetric gap series, have been discussed respectively for β≥1−p/m>0 andk≥2(m/p). Moreover, it is shown that every function inV p(k,m) arep-valent close-to-convex; hencep-valent; ifk<2 (1+m/p).
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References
Aharonov D., Friedland S.,On an inequality connected with the coefficient conjecture for functions of bounded boundary rotation, Ann. Acad. Sci. Fenn. Ser. A. Math.524 (1972), 1–14.
Brannan D. A., Clunie J. G., Kirwan W. E.,On the coefficient problem for functions of bounded boundary rotation, Ann. Acad. Sci. Fenn. Ser. AI Math.523 (1973), 1–18.
Kaplan W.,Close-to-convex schlicht functions, Michigan Math. J.1 (1952), 169–185.
Koepf W.,Coefficients of symmetric functions of bounded boundary rotation, Proc. Amer. Math. Soc.105 (2) (1989), 324–329.
Leach R. J.,Multivalent and meromorphic functions of bounded boundary rotation, Can. J. Math. Vol. XXVII1 (1975), 186–199.
Livingston A. E.,p-valent close-to-convex functions, Trans. Amer. Math. Soc.115 (1965), 161–179.
Mishra A. K., Mahapatra C. K., Pradhan M.,Convex hulls and extreme points of classes of multivalent functions defined by gap power series, Indian J. Pure Appl. Math.15(8), 889–898 August (1984).
Paatero V.,Über die Konforme Abbildung von Gebieten deren Ränder von beschränkter Drehung Sind, Ann. Acad. Sci., Fenn. Ser. A (33)9 (1931), 1–78.
Pommerenke Ch.,On the coefficients of close-to-convex functions, Michigan Math. J.9 (1962), 259–269.
Robertson M. S.,Multivalently Starlike functions, Duke Math. J.20 (1953), 539–549.
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The research of the first author was supported by UGC New Delhi Major Research Project Grant No F-8-2/92 (SR-I), D 9.6.93.
The research was done while the second author visited Berhampuv University from S.K.C.G. College, Paralakemundi under U.G.C. New Delhi, Teacher Fellowship Scheme, Grant No F. 9-22/92 (CD-4) D 25.10.1993.
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Mishra, A.K., Choudhury, M. Coefficients of multivalent symmetric functions of bounded boundary rotation. Rend. Circ. Mat. Palermo 43, 403–412 (1994). https://doi.org/10.1007/BF02844251
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DOI: https://doi.org/10.1007/BF02844251
Key Words and phrases
- m fold gap series
- p-valent close-to-convex functions of order β
- multivalent functions of bounded boundary rotation
- coefficient estimate etc