Measuring the Hubble constant through the galaxy pairwise peculiar velocity
| Autor: | Zhang, Wangzheng, Chu, Ming-chung, Liao, Shihong, Yeung, Shek, Hu, Hui-Jie |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | The Hubble constant $H_0$, the current expansion rate of the universe, is one of the most important parameters in cosmology. The cosmic expansion regulates the mutually approaching motion of a pair of celestial objects due to their gravity. Therefore, the mean pairwise peculiar velocity of celestial objects, which quantifies their relative motion, is sensitive to both $H_0$ and the dimensionless total matter density $\Omega_m$. Based on this, using the Cosmicflows-4 data, we measured $H_0$ for the first time via the galaxy pairwise velocity in the nonlinear and quasi-linear range. Our results yield $H_0=75.5\pm1.4$ km s$^{-1}$ Mpc$^{-1}$ and $\Omega_m=0.311^{+0.029}_{-0.028}$ . The uncertainties of $H_0$ and $\Omega_m$ can be improved to around 0.6% and 2%, respectively, if the statistical errors become negligible in the future. Comment: 10 pages, 3 main + 2 appendix figures, accepted for publication in ApJL |
| Databáze: | arXiv |
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