You are here: Home / Members / Postdoctoral Researchers / Sébastien Clesse

Sébastien Clesse

Post-doctoral Researcher (BELSPO, mandat de retour)

Personal website :


Research Interests:

  • Cosmic Inflation
  • Cosmic Microwave Background (CMB)
  • 21cm cosmic background
  • Theories of modified gravity



Formation and Experience:

  • 11/2013 - now : Post-doctoral Researcher (BELSPO, mandat de retour),

Namur Center for Complex Systems, Department of Mathematics, University of Namur

  • 10/2012 - 11/2013 : Post-doctoral Researcher (Alexander Von Humboldt Fellow)

T70 group, Theoretical Physics of the Universe, Technical University of Munich (TUM), Excellence Cluster Universe

  • 09/2012 - 10/2013 : Post-doctoral Researcher (Alexander Von Humboldt Fellow)

Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University

  • 09/2011 - 09/2012 : Post-doctoral Researcher (Wiener-Anspach Fellow)

Department of Applied Mathematics and Theoretical Physics (DAMTP), Cambridge University

  • 09/2007 - 09/2011 : PhD (FRIA) in Theoretical Physics (Cosmology)

Service de Physique Théorique (SPT), Université Libre de Bruxelles (ULB and Center for Cosmology, Phenomenology and Particle Physics (CP3), University of Louvain (UCL)

Supervisors:  Pr. M. Tytgat (ULB) and Pr. C. Ringeval (UCL)

  • 09/2006 - 09/2007 : Diplôme d'Etudes Approfondies (DEA) in Theoretical and Mathematical Physics, University of Louvain (UCL)
  • 09/2004 - 09/2006 : Master Degree in Physics, University of Namur
  • 09/2002 - 06/2004 : Bachelor Degree (candidatures) in Physics, University of Namur


Summary of my research activities :

Since the 1990's and the COBE experiment, the cosmology has entered into an era of high precision. Measurements of the anisotropies in the Cosmic Microwave Background (CMB)  have become increasingly accurate. The observations of Type Ia supernovae have permitted to put in evidence the present acceleration of the Universe expansion.   Combined with the distribution of the large scale structures (LSS), these observations have lead to the establishment of the concordance cosmological model.  Its main ingredients are the dark matter and the dark energy, whose origins still have to be understood.  The model also requires adiabatic, Gaussian and nearly scale-invariant initial conditions for the density perturbations.  These can be provided by a primordial phase of quasi exponential expansion, called inflation. My research activities mainly focus on inflation, on theories of modified gravity (that aim to explain the late-time acceleration of the expansion), and on their confrontation to the CMB and LSS observations, as well as to possible future observations of the 21-cm cosmological signal.

planck CMB anisotropies

The Cosmic Microwave Background temperature anisotropies seen by Planck (source: ESA-Planck website)