Contemporary statistical analyses examine the geometric structure of obtained time series embedded with differing dimensions. FFT transforms the time domain into a frequency domain, and examines the series for periodicity. The analysis produces a power spectrum , the degree to which each frequency contributes to the series. If the series is periodic, then the resulting power spectrum reveals peak power at the driving frequency. Brown noise has slope equal to -2.
Pink noise is also a major player in the area of complexity , our next topic.