@article{ThielRomanoSchwarzetal.2001,
  author    = {Thiel, Marco and Romano, Maria Carmen and Schwarz, Udo and Kurths, J{\"u}rgen and Hasinger, G{\"u}nther and Belloni, Tomaso},
  title     = {Nonlinear Time series analysis of the X-ray flux of compact objects},
  issn      = {0004-640x},
  year      = {2001},
  abstract  = {We analyse the X-ray light curves of compact objects using linear and nonlinear time series analysis methods. A Power Density Spectrum (PDS) describes the overall second order properties of the observed data well. To look beyond we propose the nonlinear Q-statistic to detect an asymmetry of the time series. This allows us to find relevant time scales. This method even grants a subclassification of the known states of X-ray sources.},
  language  = {en}
}