Recent Submissions

  • Z2-Thurston Norm and Complexity of 3-Manifolds, II 

    [OWP-2017-36] Jaco, William; Rubinstein, J. Hyam; Spreer, Jonathan; Tillmann, Stephan (Mathematisches Forschungsinstitut Oberwolfach, 2017-12-20)
    In this sequel to earlier papers by three of the authors, we obtain a new bound on the complexity of a closed 3-manifold, as well as a characterisation of manifolds realising our complexity bounds. As an application, we ...
  • Gradient Canyons, Concentration of Curvature, and Lipschitz Invariants 

    [OWP-2017-35] Paunescu, Laurentiu; Tibăr, Mihai-Marius (Mathematisches Forschungsinstitut Oberwolfach, 2017-12-13)
    We find new bi-Lipschitz invariants of holomorphic functions of two variables by using the gradient canyons and by combining analytic and geometric viewpoints on the concentration of curvature.
  • Bredon Cohomology and Robot Motion Planning 

    [OWP-2017-34] Farber, Michael; Grant, Mark; Lupton, Gregory; Oprea, John (Mathematisches Forschungsinstitut Oberwolfach, 2017-11-29)
    In this paper we study the topological invariant ${\sf {TC}}(X)$ reflecting the complexity of algorithms for autonomous robot motion. Here, $X$ stands for the configuration space of a system and ${\sf {TC}}(X)$ is, roughly, ...
  • Experimenting with Zariski Dense Subgroups 

    [OWP-2017-31] Detinko, Alla; Flannery, Dane; Hulpke, Alexander (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-28)
    We give a method to describe all congruence images of a finitely generated Zariski dense group $H\leq SL(n, \mathbb{R})$. The method is applied to obtain efficient algorithms for solving this problem in odd prime degree ...
  • The Varchenko Determinant of a Coxeter Arrangement 

    [OWP-2017-33] Pfeiffer, Götz; Randriamaro, Hery (Mathematisches Forschungsinstitut Oberwolfach, 2017-11-24)
    The Varchenko determinant is the determinant of a matrix defined from an arrangement of hyperplanes. Varchenko proved that this determinant has a beautiful factorization. It is, however, not possible to use this factorization ...
  • Looking Back on Inverse Scattering Theory 

    [OWP-2017-24] Colton, David; Kress, Rainer (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-05)
    We present an essay on the mathematical development of inverse scattering theory for time-harmonic waves during the past fifty years together with some personal memories of our participation in these events.
  • GAP Functionality for Zariski Dense Groups 

    [OWP-2017-22] Detinko, Alla; Flannery, Dane; Hulpke, Alexander (Mathematisches Forschungsinstitut Oberwolfach, 2017-09-14)
    In this document we describe the functionality of GAP [4] routines for Zariski dense or arithmetic groups that are developed in [1, 2, 3]. The research underlying the software was supported through the programme "Research ...
  • Geometry of Free Loci and Factorization of Noncommutative Polynomials 

    [OWP-2017-23] Helton, J. William; Klep, Igor; Volčič, Jurij; Helton, J. William (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-02)
    The free singularity locus of a noncommutative polynomial f is defined to be the sequence $Z_n(f)=\{X\in M_n^g : \det f(X)=0\}$ of hypersurfaces. The main theorem of this article shows that f is irreducible if and only if ...
  • Composition of Irreducible Morphisms in Coils 

    [OWP-2017-32] Chaio, Claudia; Malicki, Piotr (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-30)
    We study the non-zero composition of n irreducible morphisms between modules lying in coils in relation with the powers of the radical of their module category.
  • Non-Extendability of Holomorphic Functions with Bounded or Continuously Extendable Derivatives 

    [OWP-2017-30] Moschonas, Dionysios; Nestoridis, Vassili (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-21)
    We consider the spaces $H_{F}^{\infty}(\Omega)$ and $\mathcal{A}_{F}(\Omega)$ containing all holomorphic functions $f$ on an open set $\Omega \subseteq \mathbb{C}$, such that all derivatives $f^{(l)}$, $l\in F \subseteq ...
  • The Colored Jones Polynomial and Kontsevich-Zagier Series for Double Twist Knots 

    [OWP-2017-29] Lovejoy, Jeremy; Osburn, Robert (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-20)
    Using a result of Takata, we prove a formula for the colored Jones polynomial of the double twist knots $K_{(-m,-p)}$ and $K_{(-m,p)}$ where $m$ and $p$ are positive integers. In the $(-m,-p)$ case, this leads to new ...
  • On an Effective Variation of Kronecker’s Approximation Theorem Avoiding Algebraic Sets 

    [OWP-2017-28] Fukshansky, Lenny; German, Oleg; Moshchevitin, Nikolay (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-19)
    Let $\Lambda \subset \mathbb R^n$ be an algebraic lattice, coming from a projective module over the ring of integers of a number field $K$. Let $\mathcal Z \subset \mathbb R^n$ be the zero locus of a finite collection of ...
  • Review of the Methods of Reflections 

    [OWP-2017-27] Ciaramella, Gabriele; Gander, Martin J.; Halpern, Laurence; Salomon, Julien (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-18)
    The methods of reflections were invented to obtain approximate solutions of the motion of more than one particle in a given environment, provided that one can represent the solution for one particle rather easily. This ...
  • Detecting Ineffective Features for Pattern Recognition 

    [OWP-2017-26] Györfi, László; Walk, Harro (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-17)
    For a binary classification problem, the hypothesis testing is studied, that a component of the observation vector is not effective, i.e., that component carries no information for the classification. We introduce nearest ...
  • Exact Rate of Convergence of k-Nearest-Neighbor Classification Rule 

    [OWP-2017-25] Györfi, László; Döring, Maik; Walk, Harro (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-16)
    A binary classification problem is considered. The excess error probability of the k-nearest neighbor classification rule according to the error probability of the Bayes decision is revisited by a decomposition of the ...
  • Reducing sub-modules of the Bergman module $\mathbb A^{(\lambda)}(\mathbb D^n)$ under the action of the symmetric group 

    [OWP-2017-19] Biswas, Shibananda; Ghosh, Gargi; Misra, Gadadhar; Roy, Subrata Shyam (Mathematisches Forschungsinstitut Oberwolfach, 2017-07-20)
    The weighted Bergman spaces on the polydisc, $\mathbb A^{(\lambda)}(\mathbb D^n)$, $\lambda>0,$ splits into orthogonal direct sum of subspaces $\mathbb P_{\boldsymbol p}\big(\mathbb A^{(\lambda)}(\mathbb D^n)\big)$ indexed ...
  • An Extension Problem and Trace Hardy Inequality for the Sublaplacian on H-Type Groups 

    [OWP-2017-20] Roncal, Luz; Thangavelu, Sundaram (Mathematisches Forschungsinstitut Oberwolfach, 2017-07-24)
    In this paper we study the extension problem for the sublaplacian on a H-type group and use the solutions to prove trace Hardy and Hardy inequalities for fractional powers of the sublaplacian.
  • Counting Curves on Toric Surfaces Tropical Geometry & the Fock Space 

    [OWP-2017-18] Cavalieri, Renzo; Johnson, Paul; Markwig, Hannah; Ranganathan, Dhruv (Mathematisches Forschungsinstitut Oberwolfach, 2017-07-17)
    We study the stationary descendant Gromov–Witten theory of toric surfaces by combining and extending a range of techniques – tropical curves, floor diagrams, and Fock spaces. A correspondence theorem is established between ...
  • The Pseudo-Hyperresolution and Applications 

    [OWP-2017-17] Nguyen, The Cuong (Mathematisches Forschungsinstitut Oberwolfach, 2017-07-04)
    Resolving objects in an abelian category by injective (projective) resolutions is a fundamental problem in mathematics, and this article aims at introducing a particular solution called “Pseudo-hyperresolutions”. This ...
  • Matrix Elements of Irreducible Representations of SU(n+1) x SU(n+1) and Multivariable Matrix-Valued Orthogonal Polynomials 

    [OWP-2017-16] Koelink, Erik; van Pruijssen, Maarten; Román, Pablo Manuel (Mathematisches Forschungsinstitut Oberwolfach, 2017-06-14)
    In Part 1 we study the spherical functions on compact symmetric pairs of arbitrary rank under a suitable multiplicity freeness assumption and additional conditions on the branching rules. The spherical functions are ...

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