osmological Constraint Precision of the Photometric and Spectroscopic Multi-probe Surveys of China Space Station Telescope (CSST)

s one of Stage IV space-based telescopes, China Space Station Telescope(CSST) can perform photometric and spectroscopic surveys simultaneously toefficiently explore the Universe in extreme precision. In this work, weinvestigate several powerful CSST cosmological probes, including cosmic shear,galaxy-galaxy lensing, photometric and spectroscopic galaxy clustering, andnumber counts of galaxy clusters, and study the capability of these probes byforecasting the results of joint constraints on the cosmological parameters. Byreferring to real observational results, we generate mock data and estimate themeasured errors based on CSST observational and instrumental designs. To studythe systematical effects on the results, we also consider a number ofsystematics in CSST photometric and spectroscopic surveys, such as theintrinsic alignment, shear calibration uncertainties, photometric redshiftuncertainties, galaxy bias, non-linear effects, instrumental effects, etc. TheFisher matrix method is used to derive the constraint results from individualor joint surveys on the cosmological and systematical parameters. We find thatthe joint constraints by including all these CSST cosmological probes cansignificantly improve the results from current observations by one order ofmagnitude at least, which gives $\Omega_m$ and $\sigma_8$ $<$1% accuracy, and$w_0$ and $w_a$ $<$5% and 20% accuracies, respectively. This indicates that theCSST photometric and spectroscopic multi-probe surveys could provide powerfultools to explore the Universe and greatly improve the studies of relevantcosmological problems.