Séminaire / Seminar 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 |
| Pages web du séminaire / Seminar's webpage |