Academic Journal

Geometry of ℑ-Stiefel manifolds

التفاصيل البيبلوغرافية
العنوان: Geometry of ℑ-Stiefel manifolds
المؤلفون: Chiumiento, Eduardo Hernán
سنة النشر: 2010
المجموعة: Universidad Nacional de La Plata (UNLP): SeDiCI (Servicio de Difusión de la Creación Intelectual)
مصطلحات موضوعية: Matemática, Banach ideal, Finsler metric, Partial isometry
الوصف: Let ℑ be a separable Banach ideal in the space of bounded operators acting in a Hilbert space ℋ and U(ℋ) ℑ the Banach-Lie group of unitary operators which are perturbations of the identity by elements in ℑ. In this paper we study the geometry of the unitary orbits {UV : U ε U(ℋ) ℑ} and {UVW * : U,W ε U(ℋ) ℑ}, where V is a partial isometry. We give a spatial characterization of these orbits. It turns out that both are included in V + ℑ, and while the first one consists of partial isometries with the same kernel of V , the second is given by partial isometries such that their initial projections and V *V have null index as a pair of projections. We prove that they are smooth submanifolds of the affine Banach space V + ℑ and homogeneous reductive spaces of U(ℋ) ℑ and U(ℋ) ℑ ×U(ℋ) ℑ respectively. Then we endow these orbits with two equivalent Finsler metrics, one provided by the ambient norm of the ideal and the other given by the Banach quotient norm of the Lie algebra of U(ℋ) ℑ (or U(ℋ) ℑ × U(ℋ)I) by the Lie algebra of the isotropy group of the natural actions. We show that they are complete metric spaces with the geodesic distance of these metrics. ; Facultad de Ciencias Exactas
نوع الوثيقة: article in journal/newspaper
وصف الملف: application/pdf; 341-353
اللغة: English
Relation: http://sedici.unlp.edu.ar/handle/10915/82501
الاتاحة: http://sedici.unlp.edu.ar/handle/10915/82501
Rights: http://creativecommons.org/licenses/by-nc-sa/4.0/ ; Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
رقم الانضمام: edsbas.65CEDB0A
قاعدة البيانات: BASE