# FACULTY & STAFF

## Christophe Golé

Professor of Mathematics and Statistics

Send E–mail | Office: Burton 309 | Phone: 585–3875 |

Christophe Golé earned his Ph.D. from Boston University. He was born in France and raised partly in Northen Africa. Golé has held positions at the University of Minnesota, ETH (Zurich), SUNY Stony Brook and University of California, Santa Cruz.

Professor Golé is the author of a book on dynamical systems, *Symplectic Twist Maps Twist Maps*.

"My research interests are in the theory of dynamical systems as it applies to Hamiltonian systems and mathematical biology. Dynamical systems is the mathematical theory that studies time evolution of systems. They have been used to model many systems from physics, economics, biology, etc. The theory's claim to fame is to be the proper setting to the mathematical notion of chaos."

"Hamiltonian systems is a subfield of dynamical systems that includes celestial mechanics and all physical, mechanical systems that conserve energy. A pendulum without friction is a simple example of Hamiltonian system. My research in that field has been centered on finding periodic orbits for these systems. I helped develop variational methods that arise from decomposing the time evolution of the system into finite time steps (leading to symplectic maps). These variational methods have the advantage of being finite dimensional. In this research, I like to use a combination of dynamical systems, linear algebra and algebraic topology and some ergodic measure theory if I need to. In this context, I came across some strange objects that I baptised ghost tori.

"My mathematical biology interest is in plant pattern formation (phyllotaxis). One well–publicized phenomenon is the very frequent occurrence of Fibonacci numbers of spirals in sunflowers, pine cones and many other plants. My colleagues Pau Atela, Scott Hotton and I have studied different mathematical models where one can prove theorems explaining this phenomenon (as well as others lesser–known phenomena). In collaboration with the Smith Botanic Garden, we also created an exhibit 'Plant Spiral: Beauty You Can Count On.'"