Closed Orbits and uniform S-instability in Geometric Invariant Theory

التفاصيل البيبلوغرافية
العنوان: Closed Orbits and uniform S-instability in Geometric Invariant Theory
المؤلفون: Bate, M., Martin, B., Roehrle, G., Tange, R.
سنة النشر: 2009
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Algebraic Geometry, Mathematics - Group Theory, 20G15, 14L24, 20E42
الوصف: In this paper we consider various problems involving the action of a reductive group $G$ on an affine variety $V$. We prove some general rationality results about the $G$-orbits in $V$. In addition, we extend fundamental results of Kempf and Hesselink regarding optimal destabilizing parabolic subgroups of $G$ for such general $G$-actions. We apply our general rationality results to answer a question of Serre concerning the behaviour of his notion of $G$-complete reducibility under separable field extensions. Applications of our new optimality results also include a construction which allows us to associate an optimal destabilizing parabolic subgroup of $G$ to any subgroup of $G$. Finally, we use these new optimality techniques to provide an answer to Tits' Centre Conjecture in a special case.
Comment: 30 pages; expanded version; small suggestions by referee incorporated; final version, to appear in Trans. AMS
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/0904.4853
رقم الأكسشن: edsarx.0904.4853
قاعدة البيانات: arXiv