Euclid: impact of nonlinear prescriptions on cosmological parameter estimation from weak lensing cosmic shear

Understand

Upcoming surveys will map the growth of large-scale structure with unprecented precision, improving our understanding of the dark sector of the Universe.

• Unfortunately, much of the cosmological information is encoded by the small scales, where the clustering of dark matter and the effects of astrophysical feedback processes are not fully understood.
• This can bias the estimates of cosmological parameters, which we study here for a joint analysis of mock Euclid cosmic shear and Planck cosmic microwave background data.
• We use different implementations for the modelling of the signal on small scales and find that they result in significantly different predictions.