Browsing 1 - Oberwolfach Preprints (OWP) by MSC "37"
Now showing items 1-17 of 17
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Applications of Nijenhuis Geometry III: Frobenius Pencils and Compatible Non-Homogeneous Poisson Structures
[OWP-2022-01] (Mathematisches Forschungsinstitut Oberwolfach, 2022-01-20)We consider multicomponent local Poisson structures of the form $\mathcal P_3 + \mathcal P_1$, under the assumption that the third order term $\mathcal P_3$ is Darboux-Poisson and non-degenerate, and study the Poisson ... -
Cocycle Superrigidity and Group Actions on Stably Finite C*-Algebras
[OWP-2017-01] (Mathematisches Forschungsinstitut Oberwolfach, 2017-01-17)Let $\Lambda $ be a countably infinite property (T) group, and let $D$ be UHF-algebra of infinite type. We prove that there exists a continuum of pairwise non (weakly) cocycle conjugate, strongly outer actions of $\Lambda ... -
Demailly’s Notion of Algebraic Hyperbolicity: Geometricity, Boundedness, Moduli of Maps
[OWP-2018-20.2] (Mathematisches Forschungsinstitut Oberwolfach, 2020-01-23)Demailly's conjecture, which is a consequence of the Green-Griffths-Lang conjecture on varieties of general type, states that an algebraically hyperbolic complex projective variety is Kobayashi hyperbolic. Our aim is to ... -
Demailly’s Notion of Algebraic Hyperbolicity: Geometricity, Boundedness, Moduli of Maps
[OWP-2018-20] (Mathematisches Forschungsinstitut Oberwolfach, 2018-10-08)Demailly's conjecture, which is a consequence of the Green-Griffiths-Lang conjecture on varieties of general type, states that an algebraically hyperbolic complex projective variety is Kobayashi hyperbolic. Our aim is to ... -
Discretization of Inherent ODEs and the Geometric Integration of DAEs with Symmetries
[OWP-2022-10] (Mathematisches Forschungsinstitut Oberwolfach, 2022-06-08)Discretization methods for differential-algebraic equations (DAEs) are considered that are based on the integration of an associated inherent ordinary differential equation (ODE). This allows to make use of any discretization ... -
Fibonacci-like unimodal inverse limit spaces
[OWP-2010-03] (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-9)We study the structure of inverse limit space of so-called Fibonacci-like tent maps. The combinatorial constraints implied by the Fibonacci-like assumption allows us to introduce certain chains that enable a more detailed ... -
Homology and $K$-Theory of Torsion-Free Ample Groupoids and Smale Spaces
[OWP-2020-20] (Mathematisches Forschungsinstitut Oberwolfach, 2020-10-09)Given an ample groupoid, we construct a spectral sequence with groupoid homology with integer coefficients on the second sheet, converging to the $K$-groups of the groupoid C*-algebra when the groupoid has torsion-free ... -
Hölder-Differentiability of Gibbs Distribution Functions
[OWP-2007-13] (Mathematisches Forschungsinstitut Oberwolfach, 2007-03-29)In this paper we give non-trivial applications of the thermodynamic formalism to the theory of distribution functions of Gibbs measures (devil’s staircases) supported on limit sets of finitely generated conformal iterated ... -
The ingram conjecture
[OWP-2010-02] (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-8)We prove the Ingram Conjecture, i.e., we show that the inverse limit spaces of every two tent maps with different slopes in the interval [1,2] are non-homeomorphic. Based on the structure obtained from the proof, we also ... -
Linking and Closed Orbits
[OWP-2013-15] (Mathematisches Forschungsinstitut Oberwolfach, 2013-06-10)We show that the Lagrangian of classical mechanics on a Riemannian manifold of bounded geometry carries a periodic solution of motion with prescribed energy, provided the potential satis es an asymptotic growth ... -
Local and Global Canonical Forms for Differential-Algebraic Equations with Symmetries
[OWP-2022-05] (Mathematisches Forschungsinstitut Oberwolfach, 2022-02-21)Linear time-varying differential-algebraic equations with symmetries are studied. The structures that we address are self-adjoint and skew-adjoint systems. Local and global canonical forms under congruence are presented ... -
Noncommutative topological entropy of endomorphismus of Cuntz Algebras
[OWP-2008-12] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-16)Noncommutative topological entropy estimates are obtained for ‘finite range’ endomorphisms of Cuntz algebras,generalising known results for the canonical shift endomorphisms. Exact values are computed for a class of ... -
Noncompact harmonic manifolds
[OWP-2013-08] (Mathematisches Forschungsinstitut Oberwolfach, 2013-04-10)The Lichnerowicz conjecture asserts that all harmonic manifolds are either flat or locally symmetric spaces of rank 1. This conjecture has been proved by Z.I. Szab ́o [Sz] for harmonic manifolds with compact universal ... -
On periodic solutions and global dynamics in a periodic differential delay equation
[OWP-2014-08] (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)Several aspects of global dynamics and the existence of periodic solutions are studied for the scalar differential delay equation $x'(t) = a(t)f(x([t-K]))$, where $f(x)$ is a continuous negative feedback function, $x \cdot ... -
Spectral Continuity for Aperiodic Quantum Systems II. Periodic Approximations in 1D
[OWP-2018-27] (Mathematisches Forschungsinstitut Oberwolfach, 2018-12-17)The existence and construction of periodic approximations with convergent spectra is crucial in solid state physics for the spectral study of corresponding Schrödinger operators. In a forthcoming work [9] this task was ... -
Weak Expansiveness for Actions of Sofic Groups
[OWP-2014-05] (Mathematisches Forschungsinstitut Oberwolfach, 2014-04-25)In this paper, we shall introduce $h$-expansiveness and asymptotical $h$-expansiveness for actions of sofic groups. By the definitions, each h-expansive action of sofic groups is asymptotically $h$-expansive. We show that ... -
The Weyl group of the Cuntz algebra
[OWP-2011-31] (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-28)The Weyl group of the Cuntz algebra $\mathcal{O}_n$ is investigated. This is (isomorphic to) the group of polynomial automorphisms $\lambda_u$ of $\mathcal{O}_n$, namely those induced by unitaries u that can be written ...