The INI has a new website!

This is a legacy webpage. Please visit the new site to ensure you are seeing up to date information.

Skip to content



Exponential growth in two-dimensional topological fluid dynamics

Boyland, P (University of Florida)
Monday 23 July 2012, 16:00-16:40

Seminar Room 1, Newton Institute


In two-dimensional multi-connected fluid regions the Thurston-Nielsen (TN) theory implies that the essential topological length of material lines grows either exponentially or linearly; the TN theory and subsequent results provide many procedures for determining which growth rate occurs. Our first application is to Euler flows. The main theorem is that there are periodic stirring protocols for which generic initial vorticity yields a solution to Euler's equations which is not periodic and further, the sup norm of the gradient of the vorticity grows exponentially in time. The second application investigates which stirring protocols maximize the efficiency of mixing in the precise, topological sense of the maximal exponential growth of per unit generator of certain push-point mapping classes on the punctured disk. Related Links - my paper's page


[ppt ] [pdf ]


The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.

Back to top ∧