Coefficient conditions for starlike functions
Glasgow mathematical journal, Tome 29 (1987) no. 1, pp. 141-142
Voir la notice de l'article provenant de la source Cambridge University Press
Let {ak} be a sequence of non-negative real numbers satisfying a1 = l and(1)Brannan [1] proved that the function(2)is close-to-convex univalent in the unit disc D. The exampleshows that the conclusion in Brannan's theorem is sharp in that sense that “close-to-convex” cannot be replaced by the stronger one: “starlike”. It is therefore of interest to see which additional condition can guarantee this stronger conclusion.
Ruscheweyh, S. Coefficient conditions for starlike functions. Glasgow mathematical journal, Tome 29 (1987) no. 1, pp. 141-142. doi: 10.1017/S0017089500006753
@article{10_1017_S0017089500006753,
author = {Ruscheweyh, S.},
title = {Coefficient conditions for starlike functions},
journal = {Glasgow mathematical journal},
pages = {141--142},
year = {1987},
volume = {29},
number = {1},
doi = {10.1017/S0017089500006753},
url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500006753/}
}
[1] 1.Brannan, D. A., On univalent polynomials, Glasgow Math. J., 11 (1970), 102–107 Google Scholar | DOI
[2] 2.Vietoris, L., Über das Vorzeichen gewisser trigonometrischer Summen, Sitzungsber, Oest. Akad. Wiss., 167(1958), 125–135 Google Scholar
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