We study an extension of Duffing's equation to three variables with external forcing. Starting from a phase-space preserving chaos, three prototypes of chaotic attractors with a dimension larger than 3 can be derived. We provide examples of hyperchaos and a ''bifractal'' in a four-dimensional how. The second-order Poincare cross section of hypercha...

We consider a sine-Gordon system, driven by an ac parametric force in the presence of loss. It is demonstrated that a breather can be maintained in a steady state at half of the external frequency. In the small-amplitude limit the effect is described by an effective nonlinear Schrodinger equation. For an arbitrary frequency of the applied field the...

We consider a sine-Gordon system, driven by an ac parametric force in the presence of loss. It is demonstrated that a breather can be maintained in a steady state at half of the external frequency. In the small-amplitude limit the effect is described by an effective nonlinear Schrodinger equation. For an arbitrary frequency of the applied field the...

We consider a sine-Gordon system, driven by an ac parametric force in the presence of loss. It is demonstrated that a breather can be maintained in a steady state at half of the external frequency. In the small-amplitude limit the effect is described by an effective nonlinear Schrodinger equation. For an arbitrary frequency of the applied field the...

We consider a sine-Gordon system, driven by an ac parametric force in the presence of loss. It is demonstrated that a breather can be maintained in a steady state at half of the external frequency. In the small-amplitude limit the effect is described by an effective nonlinear Schrodinger equation. For an arbitrary frequency of the applied field the...

What does the center of mass motion of the hydrogen atom in a magnetic field look like? Is it similar to the uniform straight-lined motion of the field-free case or does it perform only tiny vibrations? We show that there is a great variety in the center of mass motion. For regular electronic motion only a bounded range of phase space is available ...

Sandkuehler, Hans Joerg (ed.)Friedrich-Ebert-Stiftung e.V. Wirtschaft...

Im Schnittfeld der Forschungsprogramme 'Ontologie, Epistemologie und methodologische Voraussetzungen der Wissenschaften' und 'Wirklichkeitskonzeptionen in Philosophie und Wissenschaften' war die Ringvorlesung des Zentrums Philosophische Grundlagen der Wissenschaften im SS 1990 dem Thema 'Wissenschaftliche Weltbilder' und der Frage nach deren Bedeut...

In the present doctoral thesis, the coherent structures of a three-dimensionally developing transitional plate boundary layer were investigated based on data from a direct numerical simulation of such a flow. In the process, the coherent structures were calculated on the basis of the definition given by Lumley, which permits to calculate these stru...