Forecast of Neutrino Cosmology from the CSST Photometric Galaxy Clustering and Cosmic Shear Surveys

Abstract

China Space Station Telescope (CSST) is a forthcoming powerful Stage IV space-based optical survey equipment. It is expected to explore a number of important cosmological problems in extremely high precision. In this work, we focus on investigating the constraints on neutrino mass and other cosmological parameters under the model of cold dark matter with a constant equation of state of dark energy (𝑤CDM), using the mock data from the CSST photometric galaxy clustering and cosmic shear surveys (i.e. 3×2pt). The systematics from galaxy bias, photometric redshift uncertainties, intrinsic alignment, shear calibration, baryonic feedback, non-linear, and instrumental effects are also included in the analysis. We generate the mock data based on the COSMOS catalog considering the instrumental and observational effects of the CSST, and make use of the Markov Chain Monte Carlo (MCMC) method to perform the constraints. Comparing to the results from current similar measurements, we find that CSST 3×2pt surveys can improve the constraints on the cosmological parameters by one order of magnitude at least. We can obtain an upper limit for the sum of neutrino mass Σ𝑚 𝜈 0.36 (0.56) eV at 68% (95%) confidence level, and Σ𝑚 𝜈 0.23 (0.29) eV at 68% (95%) confidence level if ignore the baryonic effect, which is comparable to the Planck results and much better than the current photometric surveys. This indicates that the CSST photometric surveys can provide stringent constraints on the neutrino mass and other cosmological parameters, and the results also can be further improved by including data from other kinds of CSST cosmological surveys.

Weak lensing constraints on dark matter-baryon interactions with 𝖭-body simulations and machine learning

“…The covariance matrix was computed using the CosmoCov code [59,60], incorporating a conservative galaxy shape noise of σ e = 0.3 [61] and the red-shift distributions of mock CSST galaxies from ref. [62]. Again, we applied the same small angular scale mask as DES does in appendix D. Remarkably, the future CSST cosmic shear sensitivity may substantially lower down the upper limit by around one to two orders compared to the DES 3×2pt likelihood.…”