Sébastien Clesse
Member since September 2007
Centre for Cosmology, Particle Physics and Phenomenology - CP3
Université catholique de Louvain
2, Chemin du Cyclotron - Box L7.01.05
B-1348 Louvain-la-Neuve
+32 10 47 3155
I am involved in the following research directions:

Cosmic inflation

The first measurements of acoustic peaks in the CMB anisotropies strongly suggest that the birth of cosmological fluctuations may have taken place during an early inflationary era of the universe.
In this domain, our activities deal with the construction of explicit models of inflation as well as the extraction of their observable consequences. Our fields of expertise comprise some actively debated subjects as the existence of features (e.g. trans-Planckian effects), inflation with non-minimally coupled scalar fields, DBI- and brane inflation as in the context of String Theory.
For all these theories, we are maintaining various numerical tools such as the ASPIC and FieldInf librairies allowing to compute reheating-consistent predictions for comparison with cosmological data.

External collaborators: Jérôme Martin (IAP, Paris, France), Vincent Vennin (Portsmouth, U.K.), Sébastien Clesse (RWTH, Aachen, Germany).

Cosmological data

Our expertise on inflation and cosmic strings is involved in the CMB data analysis of the PLANCK satellite.
Our current efforts concern the study of future CMB polarization experiments, ground based, and in space, as the CORE satellite.
We are part of the EUCLID collaboration and interested in the impact of high precision measurements of the matter power spectra of the large scale structures for cosmic inflation.
We are also involved in the LISA project, the giant space interferometer dedicated to gravitational wave astronomy, which should open a new window on cosmic string physics and other early universe phenomena.
Another direction concerns the 21cm cosmological radiation. This radiation is emitted by neutral hydrogen atoms and should shed light into the so-called "dark ages": from the recombination to the reionisation of the universe by the first stars. This new observable is expected to be sensitive to the nature of dark matter as well as to some properties of the inflationary era.

External collaborators: Sébastien Clesse (RWTH, Aachen), V. Vennin (Portsmooth, U.K.), CORE Coll., Euclid Coll., eLISA Coll.

Show past projects.
Publications in CP3
Showing 5 publications over 6. Show all publications.
All my publications on Inspire


Observational signatures of a non-singular bouncing cosmology
Marc Lilley, Larissa Lorenz, Sebastien Clesse
[Abstract] [PDF] [Journal] Published in JCAP 06 (2011) 004.
Refereed paper. 19th April.


Hybrid inflation along waterfall trajectories
Sébastien Clesse
[Abstract] [PDF] [Journal] updated version accepted for publication in Phys.Rev.D.
Refereed paper. 23rd June.
Initial conditions in hybrid inflation: exploration by MCMC technique
Sébastien Clesse
[Abstract] [PDF] Proceedings of the 2010 Moriond Conference - Cosmology Session
Contribution to proceedings. 23rd June.
Anamorphosis in Hybrid Inflation: How to avoid fine-tuning of Initial Conditions?
Sébastien Clesse
[Abstract] [PDF] [Journal] AIP Proceedings of the "Invisible Universe" conference, Palais de l'Unesco, Paris, 29th June to 4th July 2008.
Contribution to proceedings. 2nd February.


Fractal initial conditions and natural parameter values in hybrid inflation
Sébastien Clesse, Christophe Ringeval, Jonathan Rocher
[Abstract] [PDF] [Journal] Published in Phys. Rev. D80, 123534 (2009)
Refereed paper. 2nd September.

[UCLouvain] - [SST] [IRMP] - [SC]
Contact : Jérôme de Favereau
Job opportunities PhD Position in Theoretical Particle Physics and Cosmology