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Weak lensing peak abundance analyses have been applied in different surveys and demonstrated to be a powerful statistics in extracting cosmological information complementary to cosmic shear two-point correlation studies. Future large surveys with high number densities of galaxies enable tomographic peak analyses. Focusing on high peaks, we investigate quantitatively how the tomographic redshift binning can enhance the cosmological gains. We also perform detailed studies about the degradation of cosmological information due to photometric redshift (photo-z) errors. We show that for surveys with the number density of galaxies $sim40,{rm arcmin^{-2}}$, the median redshift $sim1$, and the survey area of $sim15000,{rm deg^{2}}$, the 4-bin tomographic peak analyses can reduce the error contours of $(Omega_{{rm m}},sigma_{8})$ by a factor of $5$ comparing to 2-D peak analyses in the ideal case of photo-z error being absent. More redshift bins can hardly lead to significantly better constraints. The photo-z error model here is parametrized by $z_{{rm bias}}$ and $sigma_{{rm ph}}$ and the fiducial values of $z_{{rm bias}}=0.003$ and $sigma_{{rm ph}}=0.02$ is taken. We find that using tomographic peak analyses can constrain the photo-z errors simultaneously with cosmological parameters. For 4-bin analyses, we can obtain $sigma(z_{{rm bias}})/z_{{rm bias}}sim10%$ and $sigma(sigma_{{rm ph}})/sigma_{{rm ph}}sim5%$ without assuming priors on them. Accordingly, the cosmological constraints on $Omega_{{rm m}}$ and $sigma_{8}$ degrade by a factor of $sim2.2$ and $sim1.8$, respectively, with respect to zero uncertainties on photo-z parameters. We find that the uncertainty of $z_{{rm bias}}$ plays more significant roles in degrading the cosmological constraints than that of $sigma_{{rm ph}}$.
In this paper, we analyze in detail with numerical simulations how the mask effect can influence the weak lensing peak statistics reconstructed from the shear measurement of background galaxies. It is found that high peak fractions are systematically
We present cosmological parameter constraints from a tomographic weak gravitational lensing analysis of ~450deg$^2$ of imaging data from the Kilo Degree Survey (KiDS). For a flat $Lambda$CDM cosmology with a prior on $H_0$ that encompasses the most r
In this manuscript of the habilitation `a diriger des recherches (HDR), the author presents some of his work over the last ten years. The main topic of this thesis is cosmic shear, the distortion of images of distant galaxies due to weak gravitationa
We derived constraints on cosmological parameters using weak lensing peak statistics measured on the $sim130~{rm deg}^2$ of the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). This analysis demonstrates the feasibility of using peak statistic
High peaks in weak lensing (WL) maps originate dominantly from the lensing effects of single massive halos. Their abundance is therefore closely related to the halo mass function and thus a powerful cosmological probe. On the other hand, however, bes