TY  - INPR
A1  - Braun, Robert
A1  - Feudel, Fred
T1  - Supertransient chaos in the two-dimensional complex Ginzburg-Landau equation
N2  - We have shown that the two-dimensional complex Ginzburg-Landau equation exhibits supertransient chaos in a certain parameter range. Using numerical methods this behavior is found near the transition line separating frozen spiral solutions from turbulence. Supertransient chaos seems to be a common phenomenon in extended spatiotemporal systems. These supertransients are characterized by an average transient lifetime which depends exponentially on the size of the system and are due to an underlying nonattracting chaotic set.
T3  - NLD Preprints - 29 
Y1  - 1996
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14099
ER  - 
TY  - BOOK
A1  - Braun, Robert
A1  - Feudel, Fred
T1  - Supertransient chaos in the two-dimensional complex Ginzburg-Landau equation
T3  - Preprint NLD
Y1  - 1996
VL  - 29
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Feudel, Fred
A1  - Seehafer, Norbert
A1  - Galanti, Barak
A1  - Rüdiger, Sten
T1  - Symmetry breaking bifurcations for the magnetohydrodynamic equations with helical forcing
N2  - We have studied the bifurcations in a three-dimensional incompressible magnetofluid with periodic boundary conditions and an external forcing of the Arnold-Beltrami-Childress (ABC) type. Bifurcation-analysis techniques have been applied to explore the qualitative behavior of solution branches. Due to the symmetry of the forcing, the equations are equivariant with respect to a group of transformations isomorphic to the octahedral group, and we have paid special attention to symmetry-breaking effects. As the Reynolds number is increased, the primary nonmagnetic steady state, the ABC flow, loses its stability to a periodic magnetic state, showing the appearance of a generic dynamo effect; the critical value of the Reynolds number for the instability of the ABC flow is decreased compared to the purely hydrodynamic case. The bifurcating magnetic branch in turn is subject to secondary, symmetry-breaking bifurcations. We have traced periodic and quasi- periodic branches until they end up in chaotic states. In particular detail we have analyzed the subgroup symmetries of the bifurcating periodic branches, which are closely related to the spatial structure of the magnetic field.
T3  - NLD Preprints - 31 
Y1  - 1996
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14317
ER  - 
TY  - JOUR
A1  - Feudel, Fred
A1  - Seehafer, Norbert
A1  - Rüdiger, Sten
T1  - Symmetry breaking bifurcations for the magnetohydrodynamic equations with helical forcing
JF  - Preprint NLD
Y1  - 1996
VL  - 31
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Feudel, Ulrike
T1  - Komplexes Verhalten in multistabilen, schwach dissipativen Systemen
N2  - Anhand eines paradigmatischen Modellbeispiels werden die Konsequenzen der Koexistenz vieler Attraktoren auf die globale Dynamik schwach dissipativer Systeme studiert. Es wird gezeigt, dass diese Systeme eine sehr reichhaltige Dynamik besitzen und extrem sensitiv gegenüber Störungen in den Anfangsbedingungen sind. Diese Systeme zeichnen sich durch eine extrem hohe Flexibilität ihres Verhaltens aus.
T3  - NLD Preprints - 34 
Y1  - 1996
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14412
ER  - 
TY  - BOOK
A1  - Feudel, Ulrike
T1  - Komplexes Verhalten in multistabilen, schwach dissipativen Systemen
T3  - Preprint NLD
Y1  - 1996
VL  - 34
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Jansen, Wolfgang
T1  - A note on the determination of the type of communication areas
N2  - The paper presents a method that determines, by standard numerical means, the type of mutual relations of fold and flip bifurcations (configured as a so-called communication area) of a map. Equation systems are developed for the computation of points where a transition between areas of different types occurs. Furthermore, it is shown that saddle area<->spring area transitions can exist which have not yet been considered in the literature. Analytical conditions of that transition are derived.
T3  - NLD Preprints - 33 
Y1  - 1996
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14339
ER  - 
TY  - BOOK
A1  - Jansen, Wolfgang
T1  - A note on the determination of the type of communication areas
T3  - Preprint NLD
Y1  - 1996
VL  - 33
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Maaß, Peter
A1  - Rieder, Andreas
T1  - Wavelet-accelerated Tikhonov-Phillips regularization with applications
N2  - Contents: 1 Introduction 1.1 Tikhanov-Phillips Regularization of Ill-Posed Problems 1.2 A Compact Course to Wavelets 2 A Multilevel Iteration for Tikhonov-Phillips Regularization 2.1 Multilevel Splitting 2.2 The Multilevel Iteration 2.3 Multilevel Approach to Cone Beam Reconstuction 3 The use of approximating operators 3.1 Computing approximating families {Ah}
T3  - NLD Preprints - 30 
Y1  - 1996
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14104
ER  - 
TY  - BOOK
A1  - Maaß, Peter
A1  - Rieder, Andreas
T1  - Wavelet-accelerated Tikhonov-Phillips regularization with applications
T3  - Preprint NLD
Y1  - 1996
VL  - 30
PB  - Univ.
CY  - Potsdam
ER  -