• Local and Global Canonical Forms for Differential-Algebraic Equations with Symmetries 

      [OWP-2022-05] Kunkel, Peter; Mehrmann, Volker (Mathematisches Forschungsinstitut Oberwolfach, 2022-02-21)
      Linear time-varying differential-algebraic equations with symmetries are studied. The structures that we address are self-adjoint and skew-adjoint systems. Local and global canonical forms under congruence are presented ...
    • 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 ...
    • A Quantitative Analysis of the “Lion-Man” Game 

      [OWP-2019-18] Kohlenbach, Ulrich; López-Acedo, Genaro; Nicolae, Adriana (Mathematisches Forschungsinstitut Oberwolfach, 2019-07-08)
      In this paper we analyze, based on an interplay between ideas and techniques from logic and geometric analysis, a pursuit-evasion game. More precisely, we focus on a discrete lion and man game with an $\varepsilon$-capture ...
    • Self-adjoint differential-algebraic equations 

      [OWP-2011-27] Kunkel, Peter; Mehrmann, Volker; Scholz, Lena (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-24)
      Motivated from linear-quadratic optimal control problems for differential-algebraic equations (DAEs), we study the functional analytic properties of the operator associated with the necessary optimality boundary value ...
    • 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. ...