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Journal of Lie Theory 29 (2019), No. 4, 1031--1044 Copyright Heldermann Verlag 2019 On Global Okounkov Bodies of Spherical Varieties Guido Pezzini Dip. di Matematica "G. Castelnuovo", Universitā "La Sapienza", Piazzale A. Moro 5, 00185 Roma, Italy pezzini@mat.uniroma1.it Henrik Seppänen Mathematisches Institut, Georg-August-Universität, Bunsenstrasse 3-5, 37073 Göttingen, Germany henrik.seppaenen@mathematik.uni-goettingen.de We define and study the global Okounkov moment cone of a projective spherical variety X, generalizing both the global Okounkov body and the moment body of X defined by Kaveh and Khovanskii. Under mild assumptions on X we show that the global Okounkov moment cone of X is rational polyhedral. As a consequence, also the global Okounkov body of X, with respect to a particular valuation, is rational polyhedral. Keywords: Spherical varieties, Newton-Okounkov bodies. MSC: 14C20, 14M27. [ Fulltext-pdf (146 KB)] for subscribers only. |