68 citations · 362 across the 19 of their papers we have counts for
19 papers
Extrapolating tipping points and simulating non-stationary dynamics of complex systems using efficient machine learning
Daniel Köglmayr, Christoph Räth
Model-free and data-driven prediction of tipping point transitions in nonlinear dynamical systems is a challenging and outstanding task in complex systems science. We propose a nov…
Weight fluctuations in (deep) linear neural networks and a derivation of the inverse-variance flatness relation
Markus Gross, Arne P. Raulf, Christoph Räth
We investigate the stationary (late-time) training regime of single- and two-layer underparameterized linear neural networks within the continuum limit of stochastic gradient desce…
Controlling dynamical systems to complex target states using machine learning: next-generation vs. classical reservoir computing
Alexander Haluszczynski, Daniel Köglmayr, Christoph Räth
Controlling nonlinear dynamical systems using machine learning allows to not only drive systems into simple behavior like periodicity but also to more complex arbitrary dynamics. F…
Linear and nonlinear market correlations: characterizing financial crises and portfolio optimization
Alexander Haluszczynski, Ingo Laut, Heike Modest +1
Pearson correlation and mutual information based complex networks of the day-to-day returns of US S&P500 stocks between 1985 and 2015 have been constructed in order to investigate…
Instability onset and scaling laws of an autooscillating turbulent flow in a complex plasma
Mierk Schwabe, Sergey Zhdanov, Christoph Räth
We study a complex plasma under microgravity conditions that is first stabilized with an oscillating electric field. Once the stabilization is stopped, the so-called heartbeat inst…
Surrogate-assisted network analysis of nonlinear time series
Ingo Laut, Christoph Räth
The performance of recurrence networks and symbolic networks to detect weak nonlinearities in time series is compared to the nonlinear prediction error. For the synthetic data of t…
Long-term monitoring of Ark 120 with Swift
M. Gliozzi, I. E. Papadakis, D. Grupe +2
We report the results of a six-month Swift monitoring campaign of Ark120, a prototypical bare Seyfert1 galaxy. The lack of intrinsic absorption combined with the nearly contemporan…
Anisotropic confinement effects in a two-dimensional plasma crystal
Ingo Laut, Sergey K. Zhdanov, Christoph Räth +2
The spectral asymmetry of the wave energy distribution of dust particles during mode-coupling induced melting, observed for the first time in plasma crystals by Couëdel et al. [Phy…
Network analysis of 3D complex plasma clusters in a rotating electric field
Ingo Laut, Christoph Räth, Lisa Wörner +6
Network analysis was used to study the structure and time evolution of driven three-dimensional complex plasma clusters. The clusters were created by suspending micron-size particl…
Correlating Fourier phase information with real-space higher order statistics
H. I. Modest, C. Räth, A. J. Banday +2
We establish for the first time heuristic correlations between harmonic space phase information and higher order statistics. Using the spherical full-sky maps of the cosmic microwa…
Collective effects in vortex movements in complex (dusty) plasmas
Mierk Schwabe, Sergey Zhdanov, Christoph Räth +3
We study the onset and characteristics of vortices in complex (dusty) plasmas using two-dimensional simulations in a setup modeled after the PK-3 Plus laboratory. A small number of…
Long-term monitoring of PKS0558-504 with Swift: the disc-corona link
M. Gliozzi, I. E. Papadakis, D. Grupe +2
PKS 0558-504 is a highly variable, X-ray bright, radio-loud, Narrow-Line Seyfert 1 galaxy with super-Eddington accretion rate and extended jets that do not dominate the emission be…
Revisiting algorithms for generating surrogate time series
C. Raeth, M. Gliozzi, I. E. Papadakis +1
The method of surrogates is one of the key concepts of nonlinear data analysis. Here, we demonstrate that commonly used algorithms for generating surrogates often fail to generate…
Search for non-Gaussianities in the WMAP data with the Scaling Index Method
G. Rossmanith, H. Modest, C. Raeth +3
In the recent years, non-Gaussianity and statistical isotropy of the Cosmic Microwave Background (CMB) was investigated with various statistical measures, first and foremost by mea…
Characterizing black hole variability with nonlinear methods: the case of the X-ray Nova 4U 1543-47
M. Gliozzi, C. Raeth, I. E. Papadakis +1
We investigate the possible nonlinear variability properties of the black hole X-ray nova 4U1543-47 to complement the temporal studies based on linear techniques, and to search for…
Non-Gaussian Signatures in the five-year WMAP data as identified with isotropic scaling indices
G. Rossmanith, C. Raeth, A. J. Banday +1
We continue the analysis of non-Gaussianities in the CMB by means of the scaling index method (SIM, Raeth, Schuecker & Banday 2007) by applying this method on the 5-year WMAP data.…
Surrogates with random Fourier Phases
Christoph Raeth, Roberto A. Monetti
The method of surrogates is widely used in the field of nonlinear data analysis for testing for weak nonlinearities. The two most commonly used algorithms for generating surrogates…
Analysing Large Scale Structure: I. Weighted Scaling Indices and Constrained Randomisation
C. Raeth, W. Bunk, M. Huber +3
The method of constrained randomisation is applied to three-dimensional simulated galaxy distributions. With this technique we generate for a given data set surrogate data sets whi…
On the Nature of X-ray Variability in Ark 564
M. Gliozzi, W. Brinkmann, C. Raeth +3
We use data from a recent long ASCA observation of the Narrow Line Seyfert 1 Ark 564 to investigate in detail its timing properties. We show that a thorough analysis of the time se…