PhD abstract

This thesis presents two research projects that are placed in the context of the two main theories of modern physics: general relativity and the standard model. — The first project aims at measuring the gravitational redshift between the PHARAO clock of the ACES-PHARAO payload (which will be docked on the ISS) and the best clocks of the different metrology laboratories. As a data processing and analysis center, the SYRTE laboratory is actively preparing the future launch of the mission by developing various dedicated software. This manuscript presents the last stage of processing which allowed to validate the expectations of the mission and which will allow to extract the violation parameter of Albert Einstein’s theory. — The second project is a dark matter research experiment located at Paris Observatory. According to the ultra-light scalar field theory, the dark matter surrounding the Earth would be at the origin of a variation of the fundamental constants of Nature. This causes a temporal oscillation of the length of the ultrastable cavity and of the optical fiber composing the Mach-Zehnder interferometer of the experiment. The development and optimization of the optical device allowed to reach a level of sensitivity low enough to place competitive constraints on the dark matter models but unfortunately did not reveal any trace of this unknown matter in the sensitivity zone of the experiment.

Key words

general relativity, space mission, ACES-PHARAO, gravitational redshift, atomic clock, standard model, dark matter, oscillation of fundamental constants, optical interferometry, fundamental physics