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Impact of baryons on weak lensing cosmological inference

Brian Lu, Zoltan Haiman

mnras/stab1978

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  • Weak lensing surveys are getting deeper

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  • More information is available on small scales
    • ~1 arcmin, 500 kpc at z=1

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  • The modelling of baryonic physics can make a difference
    • with baryons vs. without baryons
    • different baryonic models

Why baryonic physics?

mnras/stab1978

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Take dark matter-only N-body

Find dark matter halos

Paint new halos with baryons

  • Hydrodynamical simulation
  • Modify weak lensing statistics
  • Modify N-body simulation

Incorporate baryonic physics into WL

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Aricò et al. (2020)

Baryonic correction model

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Matter power spectrum

  • Our matter power spectrum is similar to Aricò et al.
  • Painting analytical profiles is very efficient

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Sfull marginalize over baryonic parameters

Sfid fix baryonic parameters

Sfull /Sfid impact of baryonic physics modelling

1σ area in ΩM–σ8 space