Résumé / Abstract Seminaire_IAP
« Constraints on dark energy and modified gravity models from CFHTLenS weak lensing  »

Martin Kilbinger
Service Astroph. (SAp), IRFU, CEA-Saclay (Gif-sur-Yvette, France)

I present results from weak gravitational lensing by the large-scale structure from CFHTLenS (Canada-France-Hawaii Lensing Survey). Using multi-band optical data over 155 square degrees, we measure the weak lensing correlation of high-redshift galaxies from small out to very large, linear scales. We reconstruct the largest maps of dark matter ever made, and infer information on cosmological parameters for flat and curved Lamda and dark-energy CDM models, and modified gravity (the latter together with redshift-space distortions from Wiggle-Z). In addition, by comparing the lensing observations with the light distribution from galaxies, we measure the relation (bias and cross-correlation) between total and luminous matter.

I will give an overview over the CFHTLenS data analysis and lensing pipeline, which is used to obtain the most accurate and reliable weak lensing measurements to date. Further, I present the likelihood and sampling methods (Population Monte Carlo, PMC) for parameter and error estimation, before I show the cosmological results.
vendredi 20 avril 2012 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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