(J. Timmer, Freiburg)
The analysis of multivariate time series has two roots. While in
mathematics linear stochastic systems were the starting point, in
physics nonlinear deterministic systems were the origin. The different
types of dynamics considered led to different notions, e.g. coherence
and phase spectra for linear stochastic systems and synchronisation for
nonlinear deterministic systems. Accordingly, different mathematical methods
have been developed to analyse time series from the different fields.
The properties of the methods have mainly be investigated for systems of the
field in which they have been developed, thus, demonstrating their
sensitivity. Since in most applications the nature of the underlying
dynamics is not known in advance but its inference is rather the goal
of the analysis, it is important to develop methods with a high specificity
for a certain type of multivariate dynamics in order to be able to draw
reliable conclusions.