Résumé / Abstract Seminaire_IAP
« Solar system and general relativity: current tests and the promise of Gaia »

Christophe Le Poncin-Lafitte
Dept. Systèmes de Référence Temps Espace (SYRTE), Obs. Paris-Meudon-Nancay (Paris, France)

Solar System is one of the best laboratory to test General Relativity (GR). We give a complete overview of what have been done during the last decade, focusing on space & ground geodesy as well as on deep space navigation by considering two different frameworks : the traditional Parameterized Post-Newtonian (PPN) approach and the Standard Model Extension (SME), enabling to study in full details possible violation from Lorentz symmetry. After discussing recent constraints obtained from Lunar Laser Ranging and Very Long Baseline Interferometry, we will consider what can be expected from the Gaia mission. Launched by the European Space Agency in late December 2013, its main objective is to survey one billion stars of our Galaxy. Gaia will also observe more than 360000 Solar System Objects (SSO). Due to an unprecedented accuracy of a few micro-arcseconds, the Gaia data processing requires a complete relativistic modeling. It gives an opportunity to carry out several GR tests. We will present first how light bending effects can improve our current knowledge of the PPN Gamma Parameter. Then, we will present SSOs simulations illustrating a sensitivity study on various gravitational tests, in particular concerning fifth force and SME formalisms.
vendredi 3 novembre 2017 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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