On the Sn-invariant F-conjecture

JOURNAL OF ALGEBRA

卷:517

Article

Moon, Han-Bom¹  Swinarski, David¹ 

[1] Fordham Univ, Dept Math, New York, NY 10023 USA

关键词: Moduli space;    Rational curves;    Birational geometry;    Nef cone;    Base point free divisor;   

DOI  :  10.1016/j.jalgebra.2018.08.030

来源: Elsevier

【 摘 要 】

By using classical invariant theory, we reduce the S-n-invariant F-conjecture to a feasibility problem in polyhedral geometry. We show by computer that for n <= 19, every integral S-n-invariant F-nef divisor on the moduli space of genus zero stable n-pointed curves is semi-ample, over arbitrary characteristic. Furthermore, for n <= 16, we show that for every integral S-n-invariant nef (resp. ample) divisor D on the moduli space, 2D is base-point-free (resp. very ample). As applications, we obtain the nef cone of the moduli space of stable curves without marked points, and the semi-ample cone of the moduli space of genus 0 stable maps to Grassmannian for small numerical values. (C) 2018 Elsevier Inc. All rights reserved.

【 授权许可】

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