Abstract
The solutions to linear extremal problems, or the support points of the classS, have been extensively studied. Every support point is known to be a monotone slit mapping whose omitted arc is analytic. Our purpose here is to consider a more general class of continuous linear functionals onS and to investigate the geometric properties of their associated extremal functions. Under appropriate hypotheses we show that the generalized support points so produced are monotone slit mappings. We then give an example where the omitted set is not an analytic arc, thus proving the existence of an extreme point which is not a support point in the usual sense. Here we follow an idea of Hamilton [4], which he used for the same purpose, but our construction is simpler.
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Duren, P., Leung, Y.J. Generalized support points of the set of univalent functions. J. Anal. Math. 46, 94–108 (1986). https://doi.org/10.1007/BF02796576
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DOI: https://doi.org/10.1007/BF02796576