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Integrating central extensions of Lie algebras via Lie 2-groups

Christoph Wockel, Chenchang Zhu (2016)

Journal of the European Mathematical Society

The purpose of this paper is to show how central extensions of (possibly infinite-dimensional) Lie algebras integrate to central extensions of étale Lie 2-groups in the sense of [Get09, Hen08]. In finite dimensions, central extensions of Lie algebras integrate to central extensions of Lie groups, a fact which is due to the vanishing of π 2 for each finite-dimensional Lie group. This fact was used by Cartan (in a slightly other guise) to construct the simply connected Lie group associated to each finite-dimensional...

Isometry invariant Finsler metrics on Hilbert spaces

Eugene Bilokopytov (2017)

Archivum Mathematicum

In this paper we study isometry-invariant Finsler metrics on inner product spaces over or , i.e. the Finsler metrics which do not change under the action of all isometries of the inner product space. We give a new proof of the analytic description of all such metrics. In this article the most general concept of the Finsler metric is considered without any additional assumptions that are usually built into its definition. However, we present refined versions of the described results for more specific...

La distance intégrée de Kobayashi sur une variété Banachique complexe

Jean-Pierre Vigué (1985)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Nel caso di una varietà di Banach complessa X , si costruisce una regolarizzata della metrica infinitesimale di Kobayashi. Se ne deduce una distanza integrata di Kobayashi e, se X è iperbolica, si mostra che questa distanza è uguale alla distanza di Kobayashi.

Length minimizing Hamiltonian paths for symplectically aspherical manifolds

Ely Kerman, François Lalonde (2003)

Annales de l’institut Fourier

In this note we consider the length minimizing properties of Hamiltonian paths generated by quasi-autonomous Hamiltonians on symplectically aspherical manifolds. Motivated by the work of Polterovich and Schwarz, we study the role, in the Floer complex of the generating Hamiltonian, of the global extrema which remain fixed as the time varies. Our main result determines a natural condition which implies that the corresponding path minimizes the positive Hofer length. We use this to prove that a quasi-autonomous Hamiltonian...

Les motifs de Tate et les opérateurs de périodicité de Connes

Abhishek Banerjee (2014)

Annales mathématiques Blaise Pascal

Dans cet article, nous définissons une catégorie M o t ˜ C des motifs sur une catégorie monoïdale symétrique ( C , , 1 ) vérifiant certaines hypothèses. Le rôle des espaces sur ( C , , 1 ) est joué par les monoïdes (non necessairement commutatifs) dans C . Pour définir les morphismes dans M o t ˜ C , nous utilisons des classes dans les groupes d’homologie cyclique bivariante. Le but est de montrer que les opérateurs de périodicité de Connes induisent des morphismes M 𝕋 2 M dans M o t ˜ C , où 𝕋 est le motif de Tate dans M o t ˜ C .

Lie group extensions associated to projective modules of continuous inverse algebras

Karl-Hermann Neeb (2008)

Archivum Mathematicum

We call a unital locally convex algebra A a continuous inverse algebra if its unit group A × is open and inversion is a continuous map. For any smooth action of a, possibly infinite-dimensional, connected Lie group G on a continuous inverse algebra A by automorphisms and any finitely generated projective right A -module E , we construct a Lie group extension G ^ of G by the group GL A ( E ) of automorphisms of the A -module E . This Lie group extension is a “non-commutative” version of the group Aut ( 𝕍 ) of automorphism...

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