Probing the Cosmological Principle with the CSST Photometric Survey

Understand

The cosmological principle states that our Universe is statistically homogeneous and isotropic at large scales.

• However, due to the relative motion of the Solar System, an additional kinematic dipole can be detected in the distribution of galaxies, which should be consistent with the dipole observed in the cosmic microwave background temperature.
• In this paper, we forecast the mock number count maps from the China Space Station Telescope photometric survey to reconstruct the kinematic dipole.
• Using the whole photometric mock data, we obtain a positive evidence for the dipole signal detection at 3 sigma confidence level, and the significance would be increased to 4 sigma when we only use the high-redshift samples with z = 1.8 to 4.