Presentation Of The Quarter Gravasco to Henri Poincaré Institute

The GRAVASCO trimester will focus on gravitation, and on the dynamics of objects in gravitational interaction. This subject is rather large. We shall discuss it through different angles. First, we will start by cases where few particles are in interaction, so that will be dealing celestial mechanics. Then, we will increase the number of particles to reach stellar dynamics, such as in globular clusters or galaxies. Then, we will go on increasing the number of objects, to talk about the dynamics of the whole universe, or large objects in the universe. This trimester will therefore discuss gravitation and objects in gravitational interaction on every scale of the observable universe. The trimester GRAVASCO will begin with a week at the Centre International de Rencontres Mathématiques, CIRM, focused on the KAM theory. Then, the trimester will settle back in Paris, at IHP, for three months with seminars, lectures, meetings and international workshops. The trimester will end with a commemoration week. We will honour Michel Hénon, who, alas, left us last spring, and who has been a great contributor in the field of selfgraviting systems. At last, we will fit in the commemoration of the bicentennial of the death of Lagrange. We will organise at IHP a day which will allow us to come back on the life and work of this renowned scholar. We will also have the opportunity to visit his grave at the nearby Pantheon. The topic of this trimester falls in with the work of Henri Poincaré, making the Institut Henri Poincaré a natural place to host such a trimester, who will gather together communities of mathematicians, physicists, and astrophysicists.