Effect of Roundoff Errors on Chaotic Orbits

Project Background: Dynamical systems generated by difference equations can exhibit a range of dynamical behaviors, from fixed points to periodic orbits to strange attractors to chaos. Part of the definition of chaos is the idea known as sensitive dependence to initial conditions. In brief this means that if the same dynamical system is given two different, but close to one another, initial conditions then as the two orbits evolve they will separate by an arbitrarily large distance. Yet the numerical precision of calculations done in the service of an orbit can yield dynamics which appear non-chaotic while if the same calculation were carried out exactly, a chaotic orbit would result.

Project Description: The student will study the behavior of difference equations such as the logistic equation. In particular the investigation will address the issue of the relationship between sensitive dependence to initial conditions, numerical precision, and coalescence (the behavior that results when two orbits which have different initial conditions eventually have the same orbit).

Desired Student Background: Ability to program in a high-level language, preferably Mathematica, C/C++, or FORTRAN, and mathematical knowledge at the level of MATH 365 Ordinary Differential Equations.