Hinke Osinga
Department of Engineering Mathematics, University of Bristol
Computing Global Stable and Unstable Manifolds
Thursday 2nd, March 14:05-14:55pm,
Carslaw Building Room 173.
Dynamical systems theory is a powerful tool to explain how the
behaviour of a dynamical system is organised. In particular, many
studies involve the investigation of the dynamics near equilibria and
how it depends on the system parameters. If one wants to study the
global dynamics of a system, it is not enough to merely carry out
these local investigations around equilibria. The key components for
explaining global dynamics are higher-dimensional objects called
stable or unstable manifolds. Even in the simplest examples, these
global manifolds must be approximated using numerical computations. If
the manifold has dimension larger than one, the computational
challenge is substantial and a very active area of research.
In this talk I will discuss algorithms for computing two-dimensional
manifolds of an equilibrium or periodic orbit of a vector field. I
will contrast computing two-dimensional manifolds in the full phase
space with computing the associated one-dimensional manifolds in a
suitably chosen Poincaré section. A two-dimensional manifold is
computed as a collection of approximate geodesic level sets, i.e
topological circles, while the computation on the Poincaré section
is set up as the continuation of a two-point boundary value problem.
My presentation involves many animated illustrations to demonstrate
the properties and usefulness of the methods.