• l-Torsion Bounds for the Class Group of Number Fields with an l -Group as Galois Group 

      [OWP-2020-11] Klüners, Jürgen; Wang, Jiuya (Mathematisches Forschungsinstitut Oberwolfach, 2020-05-04)
      We describe the relations among the $\ell$-torsion conjecture for $\ell$-extensions, the discriminant multiplicity conjecture for nilpotent extensions and a conjecture of Malle giving an upper bound for the number of ...
    • Maximal Quaternion Orders in Quadratic Extensions - in Hurwitz’s Diaries 

      [OWP-2020-16] Oswald, Nicola; Steuding, Jörn (Mathematisches Forschungsinstitut Oberwolfach, 2020-08-03)
      We present and comment on some unpublished work of Adolf Hurwitz on quaternion arithmetic from his diaries.
    • Multivariate Hybrid Orthogonal Functions 

      [OWP-2020-04] Bracciali, Cleonice F.; Pérez, Teresa E. (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-12)
      We consider multivariate orthogonal functions satisfying hybrid orthogonality conditions with respect to a moment functional. This kind of orthogonality means that the product of functions of different parity order ...
    • Nonexistence of Subcritical Solitary Waves 

      [OWP-2020-06] Kozlov, Vladimir; Lokharu, Evgeniy; Wheeler, Miles H. (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-15)
      We prove the nonexistence of two-dimensional solitary gravity water waves with subcritical wave speeds and an arbitrary distribution of vorticity. This is a longstanding open problem, and even in the irrotational case there ...
    • Rational Functions with Small Value Set 

      [OWP-2020-05] Bartoli, Daniele; Borges, Herivelto; Quoos, Luciane (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-14)
      In connection with Galois Theory and Algebraic Curves, this paper investigates rational functions $h(x) = f(x)/g(x) \in \mathbb{F}_q(x)$ for which the value set $V_h = {\{h(α) | α \in \mathbb{F}_q \cup\{\infty\}}\}$ is ...
    • Singularities and Bifurcations of Pseudospherical Surfaces 

      [OWP-2020-08] Brander, David; Tari, Farid (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-17)
      We study singularities and bifurcations of constant negative curvature surfaces in Euclidean 3-space via their association with Lorentzian harmonic maps. This preprint presents the basic results on this, the full proofs ...
    • Space-Time Euler Discretization Schemes for the Stochastic 2D Navier-Stokes Equations 

      [OWP-2020-12] Bessaih, Hakima; Millet, Annie (Mathematisches Forschungsinstitut Oberwolfach, 2020-05-06)
      We prove that the implicit time Euler scheme coupled with finite elements space discretization for the 2D Navier-Stokes equations on the torus subject to a random perturbation converges in $L^2(\Omega)$, and describe the ...
    • Splitting Necklaces, with Constraints 

      [OWP-2020-03] Jojic, Dusko; Panina, Gaiane; Zivaljevic, Rade (Mathematisches Forschungsinstitut Oberwolfach, 2020-02-11)
      We prove several versions of Alon's "necklace-splitting theorem", subject to additional constraints, as illustrated by the following results. (1) The "almost equicardinal necklace-splitting theorem" claims that, without ...