SCIENTIFIC RATIONALE

Recent advances in dynamical systems' theory render clear that chaos plays an important role in the dynamical evolution of various astronomical systems ranging from the planetary to the galactic or cosmological scales. Chaos is also important in understanding the morphological structure and kinematics of astronomical systems.

The purpose of the conference is to present the state of the art research in applications of the theory of chaos in astronomy. Astronomy was the field of science where the theory of chaos originated. Chaos is an essential ingredient of our present knowledge of how are the physical laws able to produce small or large scale structures in the Universe, like solar systems, stellar clusters, galaxies, clusters of galaxies or superclusters. Current research on these subjects involves combined notions from chaotic dynamics, celestial mechanics, galactic dynamics, observational astronomy, cosmology and relativity. Furthermore, the results from such research are of both theoretical and practical value in a variety of scientific fields such as quantum and stellar physics, seismology, biology or the medical sciences.

TOPICS

Fundamental concepts, methods and tools: Emphasis will be placed on the common elements the theory of chaos as applied in various types of astronomical systems. Furthermore, the most efficient methods and tools of detection of chaos, as well as the study of global dynamics in astronomical systems will be discussed.

Chaos in Solar System dynamics:In the few body problem, chaos can cause large scale diffusion of the orbits of solar bodies in phase space. This problem is of particular importance in the dynamics of particular populations in the solar system and of the planets in exosolar planetary systems.

Chaos in large N-Body systems and in galactic dynamics: In the case of galactic dynamics, chaos is known to play a key role near the main resonances of rotating galaxies and near the centers of galaxies (of all types) with central mass concentrations. Chaotic orbits often support rather than destroying the self-consistency of galactic structures such as bars, spiral arms, or triaxial configurations. Chaos plays a role also in the secular evolution and self-organization of such systems. Hydrodynamic simulations enhance the picture obtained by stellar dynamical self-consistent models. It has recently been proposed to measure chaos in the stream lines of gas flow in disk galaxies. Recent photometric or kinematical observations suggest that there may be observational imprints of chaos in galaxies. A final topic concerns the Dynamics of the Milky Way, in which there are now observations of all 6 phase-space coordinates for a number of stars.

Statistical Mechanics of systems with regular and chaotic orbits: Chaos in a dynamical system is produced by instabilities due to the non-linearity of physical laws. The degree of chaos in a system influences its statistical mechanical properties. Chaos provides one of the main mechanisms of entropy production. A consistent statistical mechanical theory for systems with coexisting regular and chaotic orbits is an important open question.

Chaos in the formation of large-scale structure in the Universe: Chaos finds wide application in the explanation of structure formation in the Universe. The theory of fractals allows for a characterization of the properties of the large scale structure of the Universe. When density perturbations become nonlinear, the overall structure formation is determined by processes such as entropy transfer and self-organization.

Other applications: There will be a special session devoted to applications of chaos in other fields of science such as quantum mechanics, solar physics, or magnetic fields.