Avoiding baryonic feedback contamination in weak lensing with Vera Rubin Observatory

At large scales, the dynamic of the Universe is dominated by dark matter and ordinary baryonic matter simply follows it. At smaller scales, ordinary matter starts to dominate, affecting survey data. This effect is described by different models based on numerical simulations, but, since the physics involved is complicated, we still do not have a trustworthy description.

Future stage IV surveys will give new insights into this physics at non-linear scales. Our current research focuses on understanding how much we can learn from large-scale galaxy clustering and lensing with Vera Rubin in the range not affected by baryonic systematics.

To do this, we generate mock data sets and we analyse them performing MCMC chains with the public code CosmoSIS considering different baryonic models and scale cuts. We expect to have new insights on the constraining power of LSST on the cosmological parameters, specifically \Omega_m and S_8, and the possible role of baryons in cosmological tension.