Now showing items 1-20 of 27

• #### Heisenberg-Weyl algebra revisited: combinatorics of words and paths ﻿

[OWP-2009-02] (Mathematisches Forschungsinstitut Oberwolfach, 2009)
The Heisenberg–Weyl algebra, which underlies virtually all physical representations of Quantum Theory, is considered from the combinatorial point of view. We provide a concrete model of the algebra in terms of paths on a ...
• #### Proof mining in metric fixed point theory and ergodic theory ﻿

[OWP-2009-05] (Mathematisches Forschungsinstitut Oberwolfach, 2009)
In this survey we present some recent applications of proof mining to the fixed point theory of (asymptotically) nonexpansive mappings and to the metastability (in the sense of Terence Tao) of ergodic averages in uniformly ...
• #### Minimal Riesz energy on the sphere for axis-supported external fields ﻿

[OWP-2009-04] (Mathematisches Forschungsinstitut Oberwolfach, 2009)
Abstract. We investigate the minimal Riesz $s$-energy problem for positive measures on the d-dimensional unit sphere $\mathbb{S}^d$ in the presence of an external field induced by a point charge, and more generally by ...
• #### Alternative iterative methods for nonexpansive mappings, rates of convergence and applications ﻿

[OWP-2009-19] (Mathematisches Forschungsinstitut Oberwolfach, 2009)
Alternative iterative methods for a nonexpansive mapping in a Banach space are proposed and proved to be convergent to a common solution to a fixed point problem and a variational inequality. We give rates of asymptotic ...
• #### Geometric quantization of integrable systems with hyperbolic singularities ﻿

[OWP-2009-01] (Mathematisches Forschungsinstitut Oberwolfach, 2009)
We construct the geometric quantization of a compact surface using a singular real polarization coming from an integrable system. Such a polarization always has singularities, which we assume to be of nondegenerate type. ...
• #### On the non-analyticity locus of an arc-analytic function ﻿

[OWP-2009-03] (Mathematisches Forschungsinstitut Oberwolfach, 2009-02-21)
A function is called arc-analytic if it is real analytic on each real analytic arc. In real analytic geometry there are many examples of arc-analytic functions that are not real analytic. Arc analytic functions appear ...
• #### Pointwise hyperbolicity implies uniform hyperbolicity ﻿

[OWP-2009-06] (Mathematisches Forschungsinstitut Oberwolfach, 2009-02-23)
We provide a general mechanism for obtaining uniform information from pointwise data. A sample result is that if a diffeomorphism of a compact Riemannian manifold has pointwise expanding and contracting continuous invariant ...

[OWP-2009-07] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-01)
• #### Classification of idempotent states on the compact quantum groups Uq(2), SUq(2) and SOq(3) ﻿

[OWP-2009-08] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-02)
• #### The contact polytope of the leech lattice ﻿

[OWP-2009-18] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-12)
The contact polytope of a lattice is the convex hull of its shortest vectors. In this paper we classify the facets of the contact polytope of the Leech lattice up to symmetry. There are 1, 197, 362, 269, 604, 214, 277, 200 ...
• #### Simple vector bundles on plane degenerations of an elliptic curve ﻿

[OWP-2009-20] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-13)
In 1957 Atiyah classified simple and indecomposable vector bundles on an elliptic curve. In this article we generalize his classification by describing the simple vector bundles on all reduced plane cubic curves. Our main ...