• Vector bundles on degenerations of elliptic curves and Yang-Baxter equations 

      [OWP-2007-04] Burban, Igor; Kreußler, Bernd (Mathematisches Forschungsinstitut Oberwolfach, 2007-03-22)
      In this paper we introduce the notion of a gemetric associative r-matrix attached to a genus one fibration with a section and irreducible fibres. It allows us to study degenerations of solutions of the classical Yang-Baxter ...
    • Very general monomial valuations of P2 and a Nagata type conjecture 

      [OWP-2013-22] Dumnicki, Marcin; Harbourne, Brian; Küronya, Alex; Roé, Joaquim; Szemberg, Tomasz (Mathematisches Forschungsinstitut Oberwolfach, 2013-10-29)
    • Virtual Polytopes 

      [OWP-2015-02] Panina, Gaiane; Streinu, Ileana (Mathematisches Forschungsinstitut Oberwolfach, 2015-04-10)
      Originating in diverse branches of mathematics, from polytope algebra and toric varieties to the theory of stressed graphs, virtual polytopes represent a natural algebraic generalization of convex polytopes. Introduced as ...
    • Weak Expansiveness for Actions of Sofic Groups 

      [OWP-2014-05] Chung, Nhan-Phu; Zhang, Guohua (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 ...
    • Weak-duality based adaptive finite element methods for PDE-constrained optimization with pointwise gradient state-constraints 

      [OWP-2010-15] Hintermüller, Michael; Hinze, Michael; Hoppe, Ronald H. W. (Mathematisches Forschungsinstitut Oberwolfach, 2010)
      Adaptive finite element methods for optimization problems for second order linear elliptic partial di erential equations subject to pointwise constraints on the $\ell^2$-norm of the gradient of the state are considered. ...
    • Weakly Complex Homogeneous Spaces 

      [OWP-2012-04] Moroianu, Andrei; Semmelmann, Uwe (Mathematisches Forschungsinstitut Oberwolfach, 2012-04-24)
      We complete our recent classification of compact inner symmetric spaces with weakly complex tangent bundle by filling up a case which was left open, and extend this classification to the larger category of compact homogeneous ...
    • Weighted Fourier inequalities for radial functions 

      [OWP-2009-26] Gorbachev, D.; Liflyand, E.; Tichonovič, S. V. (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-19)
      Weighted $L^p(\mathbb{R}^n) \to L^q(\mathbb{R}^n)$ Fourier inequalities are studied. We prove Pitt-Boas type results on integrability with power weights of the Fourier transform of a radial function.
    • Weighted Surface Algebras: General Version 

      [OWP-2019-07] Erdmann, Karin; Skowroński, Andrzej (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-28)
      We introduce general weighted surface algebras of triangulated surfaces with arbitrarily oriented triangles and describe their basic properties. In particular, we prove that all these algebras, except the singular disc, ...
    • A Well-Posedness Result for Viscous Compressible Fluids with Only Bounded Density 

      [OWP-2018-10] Danchin, Raphaël; Fanelli, Francesco; Paicu, Marius (Mathematisches Forschungsinstitut Oberwolfach, 2018-05-28)
      We are concerned with the existence and uniqueness of solutions with only bounded density for the barotropic compressible Navier-Stokes equations. Assuming that the initial velocity has slightly sub-critical regularity and ...
    • The Weyl group of the Curtz algebra 

      [OWP-2011-31] Conti, Roberto; Hong, Jeong Hee; Szymański, Wojciech (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 ...
    • Weyl-Titchmarsh Functions of Vector-Valued Sturm-Liouville Operators on the Unit Interval 

      [OWP-2008-13] Chelkak, Dmitry; Korotyaev, Evgeny (Mathematisches Forschungsinstitut Oberwolfach, 2008)
      The matrix-valued Weyl-Titchmarsh functions $M(\lambda)$ of vector-valued Sturm-Liouville operators on the unit interval with the Dirichlet boundary conditions are considered. The collection of the eigenvalues (i.e., poles ...
    • Yet another algorithm for the symmetric eigenvalue problem 

      [OWP-2016-02] Aurentz, Jared L.; Mach, Thomas; Vandebril, Raf; Watkins, David S. (Mathematisches Forschungsinstitut Oberwolfach, 2016-05-10)
      In this paper we present a new algorithm for solving the symmetric matrix eigenvalue problem that works by first using a Cayley transformation to convert the symmetric matrix into a unitary one and then uses Gragg’s ...
    • 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 ...
    • Zeta functions of 3-dimensional p-adic Lie algebras 

      [OWP-2007-10] Klopsch, Benjamin; Voll, Christopher (Mathematisches Forschungsinstitut Oberwolfach, 2007-03-26)
      We give an explicit formula for the subalgebra zeta function of a general 3-dimensional Lie algebra over the $p$-adic integers $\mathbb{Z}_p$. To this end, we associate to such a Lie algebra a ternary quadratic form over ...