Feix-Kaledin metric on the total spaces of cotangent bundles to K\'ahler quotients

التفاصيل البيبلوغرافية
العنوان: Feix-Kaledin metric on the total spaces of cotangent bundles to K\'ahler quotients
المؤلفون: Abasheva, Anna
المصدر: Int. Math. Res. Not., 2021, rnab047
سنة النشر: 2020
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Differential Geometry, 53C26, 14L24
الوصف: In this paper we study the geometry of the total space $Y$ of a cotangent bundle to a K\"ahler manifold $N$ where $N$ is obtained as a K\"ahler reduction from $\mathbb C^n$. Using the hyperk\"ahler reduction we construct a hyperk\"ahler metric on $Y$ and prove that it coincides with the canonical Feix-Kaledin metric. This metric is in general non-complete. We show that the metric completion $\tilde Y$ of the space $Y$ is equipped with a structure of a stratified hyperk\"ahler space. We give a necessary condition for the Feix-Kaledin metric to be complete using an observation of R.Bielawski. Pick a complex structure $J$ on $\tilde Y$ induced from quaternions. Suppose that $J\ne\pm I$ where $I$ is the complex structure whose restriction to $Y = T^*N$ is induced by the complex structure on $N$. We prove that the space $\tilde{Y}_J$ admits an algebraic structure and is an affine variety.
Comment: 34 pages; fixed two mistakes (see Prop. 2.16 and Subs. 3.1) insignificant to the proof of the main results, improved some statements, added examples
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2007.05773
رقم الأكسشن: edsarx.2007.05773
قاعدة البيانات: arXiv