Journées Scientifiques de l'Action Thématique GRAM

Session

Métrologie Temps-Espace

26 nov. 2026, 13:30

Amphi Pierre-Gilles de Gennes (Université Paris Cité)

14. Probing Ultralight Dark Matter with Molecular Spectroscopy Referenced to an Optical Network

26/11/2026 13:30

Ultralight bosonic dark matter may induce oscillations of fundamental constants such as the fine-structure constant α and the proton-to-electron mass ratio μ, which can be searched for through precision spectroscopy. We present a molecular spectroscopy platform developed to search for such signals using the REFIMEVE optical frequency dissemination network. An ultrastable optical reference at...

18. Construction of an 171Yb Optical Lattice Clock for Geodetic Exporation

26/11/2026 14:00

Optical lattice clocks have progressed swiftly over the past decade, now outperforming state-of-the-art microwave clocks by more than two orders of magnitude in both stability and accuracy, reaching a level of control of the frequency of 18 digits or better. This opens up new applications in fundamental physics, astronomy and Earth science. In this context, LTE initiated the development of a...

19. Low and high repetition rate two-colors satellite laser ranging capabilities at the Grasse optical ground station

26/11/2026 14:30

The Grasse optical ground station (GRSM-7845) contributes to the International Laser Ranging Service (ILRS) by providing Satellite and Lunar Laser Ranging observations since 2009 with almost the same instrumental setup. If the current setup is still relevant for Lunar Laser Ranging (LLR), it does not allow to answer to the millimeter challenge required for the scientific applications in space...

23. REFIMEVE+

26/11/2026 15:30

TBW