arXiv subjects

Martin Laubinger

Publications and source records attributed to Martin Laubinger.

5 recordsLinked to original sources

arXiv2014

Holomorphic current groups -- Structure and Orbits

Let K be a finite-dimensional, 1-connected complex Lie group, and let Σ_k=Σ- {p_1,\ldots,p_k\} be a compact connected Riemann surface Σ, from which we have extracted k > 0 distinct points. We study in this article the regular Frechet-Lie group O(Σ_k,K) of holomorphic maps from Σ_k to K and its central extension \widehat{O(Σ_k,K)}. We feature especially the automorphism groups of these Lie groups as well as the coadjoint orbits of \widehat{O(Σ_k,K)} which we link to flat K-bundles on Σ_k.

math.AT↗

arXiv2011

Harmonic analysis on Heisenberg--Clifford Lie supergroups

We define a Fourier transform and a convolution product for functions and distributions on Heisenberg--Clifford Lie supergroups. The Fourier transform exchanges the convolution and a pointwise product, and is an intertwining operator for the left regular representation. We generalize various classical theorems, including the Paley--Wiener--Schwartz theorem, and define a convolution Banach algebra.

math.RT↗

arXiv2010

Infinite-dimensional supermanifolds over arbitrary base fields

In his recent investigation of a super Teichmüller space, Sachse (2007), based on work of Molotkov (1984), has proposed a theory of Banach supermanifolds using the `functor of points' approach of Bernstein and Schwarz. We prove that the the category of Berezin-Kostant-Leites supermanifolds is equivalent to the category of finite-dimensional Molotkov-Sachse supermanifolds. Simultaneously, using the differential calculus of Bertram-Glöckner-Neeb (2004), we extend Molotkov-Sachse's approach to supermanifolds modeled on Hausdorff topological super-vector spaces over an arbitrary non-discrete Hausdorff topological base field of characteristic zero. We also extend to locally k-omega base fields the `DeWitt' supermanifolds considered by Tuynman in his monograph (2004), and prove that this leads to a category which is isomorphic to the full subcategory of Molokov-Sachse supermanifolds modeled on locally k-omega spaces.

math.DG↗

arXiv2009

A Lie algebra for Frölicher groups

Frölicher spaces form a cartesian closed category which contains the category of smooth manifolds as a full subcategory. Therefore, mapping groups such as C^\infty(M,G) or \Diff(M), but also projective limits of Lie groups are in a natural way objects of that category, and group operations are morphisms in the category. We call groups with this property Frölicher groups. One can define tangent spaces to Frölicher spaces, and in the present article we prove that, under a certain additional assumption, the tangent space at the identity of a Frölicher group can be equipped with a Lie bracket. We discuss an example which satisfies the additional assumption.

math.DG↗

arXiv2007

Complex Structures on Principal Bundles

Holomorphic principal G-bundles over a complex manifold M can be studied using non-abelian cohomology groups H^1(M,G). On the other hand, if M=Σis a closed Riemann surface, there is a correspondence between holomorphic principal G-bundles over Σand coadjoint orbits in the dual of a central extension of the Lie algebra C^\infty(Σ, \g). We review these results and provide the details of an integrability condition for almost complex structures on smoothly trivial bundles. This article is a shortened version of the author's Diplom thesis.

math.DG↗