4 papers
Semiconjugacies to angle-doubling
Philip Boyland
A simple consequence of a theorem of Franks says that whenever a continuous map, , is homotopic to angle doubling on the circle it is semiconjugate to it. We show that when this…
Dynamics of two-dimensional time-periodic Euler fluid flows
Philip Boyland
This paper investigates the dynamics of time-periodic Euler flows in multi-connected, planar fluid regions which are ``stirred'' by the moving boundaries. The classical Helmholtz t…
Topological fluid mechanics of point vortex motions
Philip Boyland, Mark Stremler, Hassan Aref
Topological techniques are used to study the motions of systems of point vortices in the infinite plane, in singly-periodic arrays, and in doubly-periodic lattices. The reduction o…
Isotopy Stability of Dynamics on Surfaces
Philip Boyland
This paper investigates dynamics that persist under isotopy in classes of orientation-preserving homeomorphisms of orientable surfaces. The persistence of periodic points with resp…