Cosmological constraints from weak lensing peak statistics with Canada-France-Hawaii Telescope Stripe 82 Survey

Abstract

We derived constraints on cosmological parameters using weak lensing peak statistics measured on the ∼ 130 deg<inf>2</inf> of the Canada–France–Hawaii Telescope Stripe 82 Survey. This analysis demonstrates the feasibility of using peak statistics in cosmological studies. For our measurements, we considered peaks with signal-to-noise ratio in the range of ν = [3, 6]. For a flat Λ cold dark matter model with only (Ω<inf>m</inf>, σ<inf>8</inf>) as free parameters, we constrained the parameters of the following relation Σ<inf>8</inf> = σ<inf>8</inf>(Ω<inf>m</inf>/0.27)α to be Σ<inf>8</inf> = 0.82 ± 0.03 and α = 0.43 ± 0.02. The α value found is considerably smaller than the one measured in two-point and three-point cosmic shear correlation analyses, showing a significant complement of peak statistics to standard weak lensing cosmological studies. The derived constraints on (Ω<inf>m</inf>, σ<inf>8</inf>) are fully consistent with the ones from either <it>WMAP</it>9 or <it>Planck</it>. From the weak lensing peak abundances alone, we obtained marginalized mean values of <f>$\\Omega _{\\rm m}=0.38^{+0.27}_{-0.24}$</f> and σ<inf>8</inf> = 0.81 ± 0.26. Finally, we also explored the potential of using weak lensing peak statistics to constrain the mass–concentration relation of dark matter haloes simultaneously with cosmological parameters.