Collet P., Eckmann J.-P.
The Definition and Measurement of the
Topological Entropy per Unit Volume
in Parabolic PDE's
(291K, postcript)

ABSTRACT.  We define the topological entropy per unit
volume in parabolic PDE's such as the complex Ginzburg-Landau
equation, and show that it exists, and is bounded by the upper
Hausdorff dimension times the maximal expansion rate. We then give a
constructive implementation of a bound on the inertial range of such
equations. Using this bound, we are able to propose a finite sampling
algorithm which allows (in principle) to measure this entropy from
experimental data.