Talk at the Azores14 Summer School in Observational Cosmology, Hangra de Heroismo (Terceira, Portugal) 1 June – 6 June 2014.
Abstract:
Supernovae type Ia (SNIa) have played a major role in cosmology for the last two decades, leading to the discovery of the accelerated expansion of our Universe, driven by Dark Energy. As we strive to improve SNIa as distance indicators we must include important new physical effects like weak gravitational lensing: the star can be magnified or de-magnified, depending on the matter-energy distribution along the light path. For this reason, the weak lensing adds a non/gaussian statistical noise on the Hubble diagram, degrading the estimate of the cosmological parameters. On the other hand, it can be used as a new cosmological probe, since it depends on the cosmology itself, especially the distribution of the matter along the line-of-sight.
In this talk I will review the current approach to weak lensing analysis of standard candles and I will show predictions for the weak lensing effects of SN for DES. In particular, I will focus on the degradation factor on the distance modulus of a SNIa induced by lensing and the constraints on the cosmology recovered by the weak lensing effects for the Dark Energy Survey.