Total Positivity in the De Concini-procesi Compactification
نویسنده
چکیده
We study the nonnegative part G>0 of the De Concini-Procesi compactification of a semisimple algebraic group G, as defined by Lusztig. Using positivity properties of the canonical basis and parametrization of flag varieties, we will give an explicit description of G>0. This answers the question of Lusztig in Total positivity and canonical bases, Algebraic groups and Lie groups (ed. G.I. Lehrer), Cambridge Univ. Press, 1997, pp. 281-295. We will also prove that G>0 has a cell decomposition which was conjectured by Lusztig.
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