Geometry and Topology in Physical Models


International PhD Programme in Mathematics, Mathematical Physics and Computer Science


10. Computer assisted proofs in Hamiltonian dynamics and celestial mechanics

Polish supervisor: Piotr Zgliczyński
Cooperating partners: Carles Simo (Universidad de Barcelona)
Amadeu Delshams (Univ. Politecnica de Catalunya, Barcelona)


The goal of this project to develop the tools for rigorous computer assisted study of the dynamics of Hamiltonian systems with emphasis on the problems coming from celestial mechanics.

The study of problems arising from celestial mechanics offers an opportunity to work on the problems in which subtle mathematics related to the preservation of the symplectic structure by the flow and the presence of large symmetry group meets very practical questions of finding a good trajectory for a spacecraft going to other planets or to their satellites, or the estimation whether a particular piece of rock travelling through the space will hit the Earth.

In Hamiltonian systems and in particular in the celestial mechanics there is a huge gap between what we can observe in the numerical simulations of and what we can prove rigorously. For example, there is a lot of simulations of the Solar system or of the formation of galaxies, which involved many bodies and span over billion of years. The question is: Can we trust these results? One possibility to approach this question are the computer assisted proofs of the existence of invariant objects, like KAM tori, invariant manifolds etc.

In the project the student may focus more on the theory or on the computations leading according to his or her preferences. She/he is expected to work on several topics from the following list
  • rigorous computations of Birkhoff normal forms,
  • rigorous integrators of ODEs dedicated to N-body problem or to Hamiltonian systems,
  • the construction the transition chain for the Arnold diffusion problem,
  • normally hyperbolic invariant manifolds,
  • versions of KAM theory amenable for computer assisted proofs,
  • the existence of choreographies in N-body problem for large N,
  • the destruction and bifurcations of invariant curves and invariant tori,
  • the influence of resonances on the dynamics,
  • the stability/instability of planetary systems.