Joannes Lange (Yale) "Probing Galaxy Formation and Cosmology in the Non-Linear Regime"

Abstract:
Current and future galaxy surveys have the potential to transform our understanding of both galaxy formation and cosmology. The distribution of galaxies and matter on small, non-linear scales (~Mpc) holds the most statistical constraining power but is also the most challenging to model. In this talk, I will concentrate on three distinct probes on small scales: galaxy clustering, galaxy-galaxy lensing and satellite kinematics. I will present new measurements of the tension between clustering and lensing in the BOSS survey. The most promising explanations for this tension, baryonic feedback, assembly bias and cosmological parameters different from the Planck CMB constraints, are discussed. Furthermore, I will present an updated, more robust analysis to extract constraints on the galaxy-halo connection from satellite kinematics. The accuracy of this approach is tested using a large number of realistic mock catalogs and shown to yield unbiased, highly competitive constraints. I then apply this updated analysis to the SDSS survey and compare the inferences from satellite kinematics to those from previous studies. Finally, I will discuss future directions for modeling non-linear scales which will allow to unlock the full potential of upcoming surveys like DESI or LSST.