### Irshad Mohammed

(Zurich)

*Towards precision cosmology: the halo model and necessary modifications*

There are several approaches to account for clustering of matter and its evolution in the Universe. One of the more successful frameworks is the halo model. In this approach, all the matter in the Universe is assumed to be in isolated haloes with mass defined by a threshold density. Despite its success over a decade and physical motivation, this approach is limited by its accuracy and precision. I will present necessary modifications in the halo model in order to achieve desired accuracy and precision in the underlying statistics of the distribution of matter, so called matter power spectrum, and to the extension weak lensing applications. Along with the non-linear clustering of dark matter, I will also target the corrections due to baryonic physics at small scales, full covariance matrix of the matter power spectrum and finally the cosmological implications due to these corrections.