http://arxiv.org/abs/1711.07467
We derive the complete super-sample covariance (SSC) of the matter and weak lensing convergence power spectra using the power spectrum response formalism to accurately describe the coupling of super-to-intra survey modes. The SSC term is completely characterized by the survey window function, the nonlinear matter power spectrum and the full first-order nonlinear power spectrum response function, which describes the response to super-survey density and tidal field perturbations. Separate universe simulations can efficiently measure these responses in the nonlinear regime of structure formation, which is necessary for lensing applications. Under the Limber and flat-sky approximations, we show that the tidal contributions, which have not been included in cosmological analyses so far, represent a significant fraction ($\approx 20-25\%$) of the total SSC, even for an isotropic survey footprint on the sky. The SSC is the dominant off-diagonal contribution to the total lensing covariance for survey sky fractions $f_{\rm sky} \lesssim 0.3$, making it important to include these tidal terms in cosmic shear analyses.
A. Barreira, E. Krause and F. Schmidt
Tue, 21 Nov 17
54/79
Comments: 17 pages + appendices; 4 figures; comments welcomed