• Nonlinear Multi-Parameter Eigenvalue Problems for Systems of Nonlinear Ordinary Differential Equations Arising in Electromagnetics 

      [OWP-2014-15] Angermann, Lutz; Shestopalov, Yury V.; Smirnov, Yury G.; Yatsyk, Vasyl V. (Mathematisches Forschungsinstitut Oberwolfach, 2014-12-20)
      We investigate a generalization of one-parameter eigenvalue problems arising in the theory of nonlinear waveguides to a more general nonlinear multiparameter eigenvalue problem for a nonlinear operator. Using an integral ...
    • Observability of systems with delay convoluted observation 

      [OWP-2014-10] Verriest, Erik I.; Ivanov, Anatoli F. (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)
      This paper analyzes finite dimensional linear time-invariant systems with observation of a delay, where that delay satisfies a particular implicit relation with the state variables, rendering the entire problem nonlinear. ...
    • On periodic solutions and global dynamics in a periodic differential delay equation 

      [OWP-2014-08] Ivanov, Anatoli F.; Trofimchuk, Sergei I. (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)
      Several aspects of global dynamics and the existence of periodic solutions are studied for the scalar differential delay equation x(t)=a(t)f(x([tK])), where f(x) is a continuous negative feedback function, $x \cdot ...
    • 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 ...
    • Slowly oscillating wave solutions of a single species reaction-diffusion equation with delay 

      [OWP-2007-12] Trofimchuk, Elena; Tkachenko, Victor; Trofimchuk, Sergei I. (Mathematisches Forschungsinstitut Oberwolfach, 2007-03-28)
      We study positive bounded wave solutions u(t,x)=ϕ(νx+ct), ϕ()=0, of equation ut(t,x)=δu(t,x)u(t,x)+g(u(th,x)), xRm(*). It is supposed that Eq. (∗) has exactly two ...
    • Square wave periodic solutions of a differential delay equation 

      [OWP-2014-09] Ivanov, Anatoli F.; Verriest, Erik I. (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)
      We prove the existence of periodic solutions of the differential delay equation ε˙x(t)+x(t)=f(x(t1)),ε>0 under the assumptions that the continuous nonlinearity f(x) satisfies the negative ...
    • Unconditional Convergence of Spectral Decompositions of 1D Dirac Operators with Regular Boundary Conditions 

      [OWP-2010-21] Djakov, Plamen; Mitjagin, Boris S. (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-19)
    • 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(λ) 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 ...