Recent Submissions

  • Categorical Linearly Ordered Structures 

    [OWP-2018-08] Downey, Rod; Melnikov, Alexander; Ng, Keng Meng (Mathematisches Forschungsinstitut Oberwolfach, 2018-04-26)
    We prove that for every computable limit ordinal $\alpha$ there exists a computable linear ordering $\mathcal{A}$ which is $\Delta^0_\alpha$-categorical and $\alpha$ is smallest such, but nonetheless for every isomorphic ...
  • On the Gauss Algebra of Toric Algebras 

    [OWP-2018-07] Herzog, Jürgen; Jafari, Raheleh; Nasrollah Nejad, Abbas (Mathematisches Forschungsinstitut Oberwolfach, 2018-04-25)
    Let $A$ be a $K$-subalgebra of the polynomial ring $S=K[x_1,\ldots,x_d]$ of dimension $d$, generated by finitely many monomials of degree $r$. Then the Gauss algebra $\mathbb{G}(A)$ of $A$ is generated by monomials of ...
  • 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 ...
  • The Sylow Structure of Scalar Automorphism Groups 

    [OWP-2018-05] Herfort, Wolfgang; Hofmann, Karl Heinrich; Kramer, Linus; Russo, Francesco G. (Mathematisches Forschungsinstitut Oberwolfach, 2018-03-22)
    For any locally compact abelian periodic group A its automorphism group contains as a subgroup those automorphisms that leave invariant every closed subgroup of A, to be denoted by SAut(A). This subgroup is again a locally ...
  • Exceptional Legendrian Torus Knots 

    [OWP-2018-04] Geiges, Hansjörg; Onaran, Sinem (Mathematisches Forschungsinstitut Oberwolfach, 2018-03-21)
    We present classification results for exceptional Legendrian realisations of torus knots. These are the first results of that kind for non-trivial topological knot types. Enumeration results of Ding-Li-Zhang concerning ...
  • The Martin Boundary of Relatively Hyperbolic Groups with Virtually Abelian Parabolic Subgroups 

    [OWP-2018-03] Dussaule, Matthieu; Gekhtman, Ilya; Gerasimov, Victor; Potyagailo, Leonid (Mathematisches Forschungsinstitut Oberwolfach, 2018-03-19)
    Given a probability measure on a finitely generated group, its Martin boundary is a way to compactify the group using the Green's function of the corresponding random walk. We give a complete topological characterization ...
  • Deformation Classification of Real Non-Singular Cubic Threefolds with a Marked Line 

    [OWP-2018-02] Finashin, Sergey; Kharlamov, Viatcheslav (Mathematisches Forschungsinstitut Oberwolfach, 2018-02-21)
    We prove that the space of pairs $(X,l)$ formed by a real non-singular cubic hypersurface $X\subset P^4$ with a real line $l\subset X$ has 18 connected components and give for them several quite explicit interpretations. ...
  • 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 ...