Résumé / Abstract Seminaire_GReCO

"Effect of peculiar motion in weak lensing"

C. Bonvin

I will present the effect of peculiar motion in weak gravitational lensing. More precisely, I will show that the cosmic shear and the convergence, evaluated in a perturbed Friedmann Universe, contain a new contribution related to galaxies'' peculiar velocities. This contribution does not affect the cosmic shear in a measurable way, since it is of second order in the velocity. However, its effect on the convergence is important, especially for redshifts z < 1. As a consequence, peculiar motion modifies also the relation between the shear and the convergence. The new relation could be used by future experiments to measure directly the peculiar velocity field of galaxies.

jeudi 26 mars 2009 - 11:00
Salle des séminaires Évry Schatzman,
Institut d'Astrophysique de Paris

Page web du séminaire / Seminar's webpage