• Low rank differential equations for hamiltonian matrix nearness problems 

      [OWP-2013-01] Guglielmi, Nicola; Kreßner, Daniel; Lubich, Christian (Mathematisches Forschungsinstitut Oberwolfach, 2013-02-08)
      For a Hamiltonian matrix with purely imaginary eigenvalues, we aim to determine the nearest Hamiltonian matrix such that so me or all eigenvalues leave the imaginary axis. Conversely, for a Hamiltonian matrix with all ...
    • Non-stationary multivariate subdivision: joint spectral radius and asymptotic similarity 

      [OWP-2013-20] Charina, Maria; Conti, Costanza; Guglielmi, Nicola; Protasov, Vladimir (Mathematisches Forschungsinstitut Oberwolfach, 2013-10-29)
      In this paper we study scalar multivariate non-stationary subdivision schemes with a general integer dilation matrix. We present a new numerically efficient method for checking convergence and Hölder ...
    • On the Derived Category of Grassmannians in Arbitrary Characteristic 

      [OWP-2013-24] Buchweitz, Ragnar-Olaf; Leuschke, Graham J.; Van den Bergh, Michel (Mathematisches Forschungsinstitut Oberwolfach, 2013-12-09)
      In this paper we consider Grassmannians in arbitrary characteristic. Generalizing Kapranov's well-known characteristic-zero results we construct dual exceptional collections on them (which are however not strong) as well ...
    • Supertropical Quadratic Forms I 

      [OWP-2013-27] Knebusch, Manfred; Rowen, Louis; Izhakian, Zur (Mathematisches Forschungsinstitut Oberwolfach, 2013)
      We initiate the theory of a quadratic form q over a semiring $R$. As customary, one can write $q(x+y)=q(x)+q(y)+b(x,y)$, where b is a companion bilinear form. But in contrast to the ring-theoretic case, the companion ...