Vincent Boucher
Former member
Research scientist in CP3 from September 2003 to April 2013
Current position: Partner at B12 Consulting.
My personal homepage
I am involved in the following research direction:

Scalar-tensor theories of gravitation

The strong equivalence principle (SEP) does not hold anymore in various extensions of General Relativity. Its violations can be revealed by the non-universality of free-falling for compact objects and we have developed a generic and effective way to test the SEP in the Cosmic Microwave Background (CMB). A violation of the SEP indeed alters the amplitude of the acoustic oscillations in the primeval plasma. Using the WMAP data, we have contrained a possible SEP violation for the baryons.

Our interests are also focused on the scalar-tensor theories of gravitation and their cosmologies. In a more specific way, we are currently studying a model where the scalar sector is conformally invariant. The effective fluid related to the non-minimally coupled scalar field differs from the other cosmological fluids of radiation by its very particular anisotropic pressure and we are studying its impact on the CMB anisotropies by modifying the CAMB code.

Past projects
Hide past projects.

I am involved in the following research direction:

Dark energy

Although the undergoing cosmic acceleration may be explained by a non-vanishing cosmological constant in Einstein gravity, various dynamical effects could very well explain current observations, all dubbed as dark energy.

Quintessence, as a light scalar field minimally coupled to gravity, is a dark energy candidate to explain the recent acceleration of the Universe expansion. The Ratra-Peebles potential and its corrected form in supergravity are under study. Using a modified version of CAMB, including perturbations of the scalar field, we use the latest SNIa and CMB observations to select acceptable points in the parameter space. Starting with the associated matter power spectrum, in collaboration with the LUTh (Paris-Meudon Obs., France) we run N-body simulations of growth of large scale structures where the background evolution is modified by quintessence. We are involved in the Dark Energy Universe Simulation Series (DEUSS) collaboration.

Another dark energy candiate involves cosmic inflation, currently the best explanation of the origin of large scale structures and CMB anisotropies. Similarly, if dark energy is a light scalar field, the current acceleration can be the consequence of quantum fluctuations during cosmic inflation, provided this one occurs at TeV scale.

External collaborators: Jean-Michel Alimi, Yann Rasera, Pier Stefano Corasaniti (Observatoire de Paris-Meudon, France). Teruaki Suyama (The University of Tokyo, Japan), Tomo Takahashi (Saga University, Japan), Masahide Yamaguchi (Tokyo Institute of Technology, Japan), Shuichiro Yokoyama (Nagoya University, Japan).

Publications in CP3
All my publications on Inspire


Introducing the Dark Energy Universe Simulation Series (DEUSS)
Y. Rasera, J-M. Alimi, J. Courtin, F. Roy, P-S. Corasaniti, A. Füzfa and V. Boucher
[Abstract] [PDF] [Journal] Invisible Universe International Conference, UNESCO-Paris, 2009. DEUS Consortium reference paper.
Contribution to proceedings. 15th July.
Imprints of dark energy on cosmic structure formation: II) Non-Universality of the halo mass function
Jérôme Courtin, Yann Rasera, Jean-Michel Alimi, Pier-Stefano Corasaniti, Vincent Boucher, André Füzfa
[Abstract] [PDF] [Journal] Published in MNRAS (410) 1911, 2011.
Refereed paper. 20th January.


Imprints of Dark Energy on Cosmic Structure Formation I) Realistic Quintessence Models and the Non-Linear Matter Power Spectrum
Jean-Michel Alimi, André Füzfa, Vincent Boucher, Yann Rasera, Jérôme Courtin, Pier-Stefano Corasaniti
[Abstract] [PDF] [Journal] Published in the Monthly Notices of the Royal Astronomical Society, 401, 775-790 (2010).
Refereed paper. 31st March.


A cosmological test for general relativity
V. Boucher
[Abstract] [PDF] Published in Gravitation & Cosmology 11 (2005) 71-74
Contribution to proceedings. 26th September.

[UCLouvain] - [SST] [IRMP] - [SC] [PHYS]
Contact : Vincent Boucher & Jérôme de Favereau
Cosmo related
Job opportunities PhD position in NA62 experiment