Testing modified gravity with large angular scale gravitational lensing

por Ue-Li Pen (CITA, University of Toronto)

lunes 10 oct. 2011 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

We present projected constraints on modified gravity models from the observational technique known as 21 cm intensity mapping, where cosmic structure is detected without resolving individual galaxies. The resulting map is sensitive to both BAO and weak lensing, two of the most powerful cosmological probes. It is found that a 200 m x 200 m cylindrical telescope, sensitive out to z=2.5, would be able to distinguish DGP from most dark energy models, and constrain the Hu & Sawicki f(R) model to |f_{R0}| < 9*10^(-6) at 95% confidence. The latter constraint makes extensive use of the lensing spectrum in the nonlinear regime. These results show that 21 cm intensity mapping is not only sensitive to modifications of the standard model's expansion history, but also to structure growth. This makes intensity mapping a powerful and economical technique, achievable on much shorter time scales than optical experiments that would probe the same era.