Testing the Equivalence Principle

MICROSCOPE colloquium II

Paris, 29-30 January 2013

Scientific Organizing Committee: T. Damour (chair), C. Lämmerzahl, S. Leon-Hirtz, G. Metris, S. Reynaud, P. Touboul, P. Wolf

Local Organizing Committee: F. Debruyère, G. Metris, M. Rodrigues, P. Touboul

The Einstein Equivalence Principle (EP) is probably the most fundamental postulate of physics. It is in particular the founding principle of general relativity and more generally the basic postulate of all geometric theories of gravitation. This central position has resulted in experimental tests of its different aspects (universality of free fall, universality of clock rates, Lorentz invariance) by numerous experiments with ever increasing precision making it one the best established postulates of physics today. However, most attempts at unification of general relativity and the standard model of particle physics lead to a violation of the EP, that would manifest itself in experimental tests. It is thus essential to pursue such tests with increasing precision and over a broad range of different experiments, as this provides one of the most accessible experimental windows to physics beyond the standard model. In this aim the MICROSCOPE project, a joined CNES-DLR-ESA mission is planned for launch in 2016 and is expected to improve present limits on a possible violation of the universality of free fall (a central EP test) by at least two orders of magnitude.

After the first colloquium held last year, this second colloquium will bring together experts in theoretical physics, space sciences, with scientists involved in the project since many years. The main objective is to prepare the scientific exploitation of the data produced by the MICROSCOPE mission. To this end the space mission, the instrument, the present mission scenario and the proposed scientific mission centre will be presented in details. Attendees are invited to present their interest and competence in exploiting the MICROSCOPE data.

Preliminary Program

  • MICROSCOPE mission status

  • Theoretical Motivations for MICROSCOPE test of the weak equivalence principle (WEP)

  • Ways of testing WEP, similarities and complementarity with MICROSCOPE

  • Details of the Microscope mission: the satellite, the instrument, the experiment and its mission scenario, the scientific mission centre...

  • Data processing approaches, phenomenology questions and other scientific returns

  • Round table discussion in preparation to the future call for data processing proposals

Link to the detailled agenda


  • The participation to the colloquium is free.

  • Please register and submit a presentation by means of this FORM.

  • Submission deadline: 10th December 2012. (closed)

  • Registration deadline: 18th January 2013.

Practical Information

Location and venue

  • The conference will be located at ONERA in Palaiseau, 20 km south of Paris (click on the link for more information).

  • For access to Onera, attendees will be asked to present their identity documents. Please, non-EU citizens must send their bio data (place and date of birth, nationality, passport no.) in advance to Fabienne Debruyère.

  • The lunchs and coffe breaks will be freely available at ONERA

  • A list of hotels can be download here: .


Some financial supports for travel is available ; please contact the organizers if needed.

Last update 26th February 2013