• Group Algebras of Compact Groups. A New Way of Producing Group Hopf Algebras over Real and Complex Fields: Weakly Complete Topological Vector Spaces 

      [OWP-2019-06] Hofmann, Karl Heinrich; Kramer, Linus (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-27)
      Weakly complete real or complex associative algebras $A$ are necessarily projective limits of finite dimensional algebras. Their group of units $A^{-1}$ is a pro-Lie group with the associated topological Lie algebra $A_{\rm ...
    • Group-Graded Rings Satisfying the Strong Rank Condition 

      [OWP-2019-22] Kropholler, Peter H.; Lorensen, Karl (Mathematisches Forschungsinstitut Oberwolfach, 2019-08-16)
      A ring $R$ satisfies the $\textit{strong rank condition}$ (SRC) if, for every natural number $n$, the free $R$-submodules of $R^n$ all have rank $\leq n$. Let $G$ be a group and $R$ a ring strongly graded by $G$ such that ...
    • Groups with Spanier-Whitehead Duality 

      [OWP-2019-23] Nishikawa, Shintaro; Proietti, Valerio (Mathematisches Forschungsinstitut Oberwolfach, 2019-09-17)
      We introduce the notion of Spanier-Whitehead $K$-duality for a discrete group $G$, defined as duality in the KK-category between two $C*$-algebras which are naturally attached to the group, namely the reduced group ...
    • Hecke duality relations of Jacobi forms 

      [OWP-2008-03] Bringmann, Kathrin; Heim, Bernhard (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-07)
      In this paper we introduce a new subspace of Jacobi forms of higher degree via certain relations among Fourier coefficients. We prove that this space can also be characterized by duality properties of certain distinguished ...
    • Heisenberg-Weyl algebra revisited: combinatorics of words and paths 

      [OWP-2009-02] Blasiak, Pawel; Duchamp, Gérard H. E.; Horzela, Andrzej; Penson, Karol A.; Solomon, Allan I. (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 ...
    • Herbrand’s Theorem as Higher Order Recursion 

      [OWP-2018-01] Afshari, Bahareh; Hetzl, Stefan; Leigh, Graham E. (Mathematisches Forschungsinstitut Oberwolfach, 2018-02-19)
      We provide a means to compute Herbrand disjunctions directly from sequent calculus proofs with cuts. Our approach associates to a first-order classical proof $\pi \vdash \exists v F$, where $F$ is quantifier free, an ...
    • Higher Finiteness Properties of Reductive Arithmetic Groups in Positive Characteristic: the Rank Theorem 

      [OWP-2011-05] Bux, Kai-Uwe; Köhl, Ralf; Witzel, Stefan (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-8)
      We show that the finiteness length of an $S$-arithmetic subgroup $\Gamma$ in a noncommutative isotropic absolutely almost simple group $\mathcal{G}$ over a global function field is one less than the sum of the local ranks ...
    • Hight functions on quaternionic Stiefel manifolds 

      [OWP-2015-10] Macías-Virgós, Enrique; Strom, Jeffrey; Tanré, Daniel; Oprea, John (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-29)
      In this note, we study height functions on quaternionic Stiefel manifolds and prove that all these height functions are Morse-Bott. Among them, we characterize the Morse functions and give a lower bound for their number ...
    • Holomorphic automorphic forms and cohomology 

      [OWP-2014-07] Bruggeman, Roelof W.; Ch'oe, Yŏng-ju; Diamantis, Nikolaos (Mathematisches Forschungsinstitut Oberwolfach, 2014-04-25)
      We investigate the correspondence between holomorphic automorphic forms on the upper half-plane with complex weight and parabolic cocycles. For integral weights at least 2 this correspondence is given by the Eichler integral. ...
    • Holonomy Groups of $G_2^*$-Manifolds 

      [OWP-2017-07] Fino, Anna; Kath, Ines (Mathematisches Forschungsinstitut Oberwolfach, 2017-03-07)
      We classify the holonomy algebras of manifolds admitting an indecomposable torsion free $G_2^*$-structure, i.e. for which the holonomy representation does not leave invariant any proper non-degenerate subspace. We realize ...
    • Homogenization of a nonlinear monotone problem with nonlinear Signorini boundary conditions in a domain with highly rough boundary 

      [OWP-2018-06] Gaudiello, Antonio; Mel'nyk, Taras A. (Mathematisches Forschungsinstitut Oberwolfach, 2018-04-16)
      We consider a domain $\Omega_\varepsilon\subset\mathbb{R}^N$, $N\geq2$, with a very rough boundary depending on~$\varepsilon$. For instance, if $N=3$ the domain $\Omega_\varepsilon$ has the form of a brush with an ...
    • Homological properties of piecewise hereditary algebras 

      [OWP-2009-11] Happel, Dieter; Zacharia, Dan (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-05)
      Let $\Lambda$ be a finite dimensional algebra over an algebraically closed field $k$. We will investigate homological properties of piecewise hereditary algebras $\Lambda$. In particular we give lower and upper bounds of ...
    • Homology and $K$-Theory of Torsion-Free Ample Groupoids and Smale Spaces 

      [OWP-2020-20] Proietti, Valerio; Yamashita, Makoto (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 ...
    • Hopf Algebras in Combinatorics, Volume 1 

      [OWP-2020-14] Grinberg, Darij; Reiner, Victor (Mathematisches Forschungsinstitut Oberwolfach, 2020-07-29)
    • Hopf Algebras in Combinatorics, Volume 2 

      [OWP-2020-15] Grinberg, Darij; Reiner, Victor (Mathematisches Forschungsinstitut Oberwolfach, 2020-07-30)
    • How Quantum Information Can Improve Social Welfare 

      [OWP-2020-13] Groisman, Berry; Mc Gettrick, Michael; Mhalla, Mehdi; Pawlowski, Marcin (Mathematisches Forschungsinstitut Oberwolfach, 2020-07-16)
      In [2, 18, 5, 19, 4] it has been shown that quantum resources can allow us to achieve a family of equilibria that can have sometimes a better social welfare, while guaranteeing privacy. We use graph games to propose ...
    • Hölder Continuity of the Spectra for Aperiodic Hamiltonians 

      [OWP-2019-05] Beckus, Siegfried; Bellissard, Jean; Cornean, Horia (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-26)
      We study the spectral location of a strongly pattern equivariant Hamiltonians arising through configurations on a colored lattice. Roughly speaking, two configurations are "close to each other" if, up to a translation, ...
    • Hölder-Differentiability of Gibbs Distribution Functions 

      [OWP-2007-13] Keßeböhmer, Marc; Stratmann, Bernd (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 ...
    • Hutchinson's Intervals and Entire Functions from the Laguerre-Pólya Class 

      [OWP-2022-19] Nguyen, Thu Hien; Vishnyakova, Anna (Mathematisches Forschungsinstitut Oberwolfach, 2022-12-12)
      We find the intervals $[\alpha, \beta (\alpha)]$ such that if a univariate real polynomial or entire function $f(z) = a_0 + a_1 z + a_2 z^2 + \cdots $ with positive coefficients satisfy the conditions $ \frac{a_{k-1}^2}{ ...
    • Hypergroups and Twin Buildings, I 

      [OWP-2023-10] French, Christopher; Zieschang, Paul-Hermann (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)
      We discuss a conjecture on thick twin buildings the verification of which is needed in order to show that thick twin buildings are mathematically equivalent to regular actions of certain twin Coxeter hypergroups. (A ...