2021/04/09 by Tianhuan Lu, Zoltán Haiman
Physics and Astronomy · #Astronomy #Astrophysics #Baryon #Cosmology #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Gravitational lens #Gravitational lensing formalism #Inference #Particle physics #Physics #Redshift #Statistical physics #Theoretical physics #Weak gravitational lensing #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stab1978
15 pages, 14 figures
arxiv created 2021/04/09 · openalex created_date 2021/04/26 · openalex publication_date 2021/07/09 · arxiv updated 2021/07/21 · openalex updated_date 2026/08/05
ABSTRACT As weak lensing surveys are becoming deeper and cover larger areas, information will be available on small angular scales down to the arcmin level. To extract this extra information, accurate modelling of baryonic effects is necessary. In this work, we adopt a baryonic correction model, which includes gas both bound inside and ejected from dark matter (DM) haloes, a central galaxy, and changes in the DM profile induced by baryons. We use this model to incorporate baryons into a large suite of DM-only N-body simulations, covering a grid of 75 cosmologies in the Ωm–σ8 parameter space. We investigate how baryons affect Gaussian and non-Gaussian weak lensing statistics and the cosmological parameter inferences from these statistics. Our results show that marginalizing over baryonic parameters degrades the constraints in Ωm–σ8 space by a factor of 2–5 compared to those with baryonic parameters fixed. We also find that combining the lensing power spectrum and peak counts can break the degeneracy between cosmological and baryonic parameters and mitigate the impact of the uncertainty in baryonic physics.