您选择的条件: Ji-Guo Zhang
  • First statistical measurement of the Hubble constant using unlocalized fast radio bursts

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Fast radio bursts (FRBs) can be used to measure the Hubble constant by employing the Macquart relation. However, at present, only a small number of FRB events are localized to their host galaxies with known redshifts. In this paper, we develop a Bayesian method to statistically measure the Hubble constant using unlocalized FRBs and galaxy catalog data, which makes it possible to constrain cosmological parameters by using a large number of FRB data without known redshift information. Using the six FRB events observed by ASKAP combined with the big bang nucleosynthesis result, we obtain $H_0=71.7^{+8.8}_{-7.4}$ km s$^{-1}$ Mpc$^{-1}$ in the simulation-based case and $H_0=71.5^{+10.0}_{-8.1}$ km s$^{-1}$ Mpc$^{-1}$ in the observation-based case ($68\%$ highest-density interval), assuming different host galaxy population parameters. We also estimate that in the next few years, using thousands of FRBs could achieve a $3\%$ precision on the random error of the Hubble constant.

  • Probing the interaction between dark energy and dark matter with future fast radio burst observations

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Interacting dark energy (IDE) scenario assumes that there exists a direct interaction between dark energy and cold dark matter, but this interaction is hard to be tightly constrained by the current data. Finding new cosmological probes to precisely measure this interaction could deepen our understanding of dark energy and dark matter. Fast radio bursts (FRBs) will be seen in large numbers by future radio telescopes, and thus they have potential to become a promising low-redshift cosmological probe. In this work, we investigate the capability of future FRBs of constraining the dimensionless coupling parameter $\beta$ in four phenomenological IDE models. We find that in the IDE models with the interaction proportional to the energy density of dark energy, about $10^5$ FRB data can give constraint on $\beta$ tighter than the current cosmic microwave background data. In all the IDE models, about $10^6$ FRB data can constrain the absolute errors of $\beta$ to less than $0.10$, providing a way to precisely measure $\beta$ by only one cosmological probe. The reconstruction of the interaction term also shows that the FRB data could help constrain the redshift evolution of interaction.

  • First statistical measurement of the Hubble constant using unlocalized fast radio bursts

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Fast radio bursts (FRBs) can be used to measure the Hubble constant by employing the Macquart relation. However, at present, only a small number of FRB events are localized to their host galaxies with known redshifts. In this paper, we develop a Bayesian method to statistically measure the Hubble constant using unlocalized FRBs and galaxy catalog data, which makes it possible to constrain cosmological parameters by using a large number of FRB data without known redshift information. Using the six FRB events observed by ASKAP combined with the big bang nucleosynthesis result, we obtain $H_0=71.7^{+8.8}_{-7.4}$ km s$^{-1}$ Mpc$^{-1}$ in the simulation-based case and $H_0=71.5^{+10.0}_{-8.1}$ km s$^{-1}$ Mpc$^{-1}$ in the observation-based case ($68\%$ highest-density interval), assuming different host galaxy population parameters. We also estimate that in the next few years, using thousands of FRBs could achieve a $3\%$ precision on the random error of the Hubble constant.

  • Probing the interaction between dark energy and dark matter with future fast radio burst observations

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Interacting dark energy (IDE) scenario assumes that there exists a direct interaction between dark energy and cold dark matter, but this interaction is hard to be tightly constrained by the current data. Finding new cosmological probes to precisely measure this interaction could deepen our understanding of dark energy and dark matter. Fast radio bursts (FRBs) will be seen in large numbers by future radio telescopes, and thus they have potential to become a promising low-redshift cosmological probe. In this work, we investigate the capability of future FRBs of constraining the dimensionless coupling parameter $\beta$ in four phenomenological IDE models. We find that in the IDE models with the interaction proportional to the energy density of dark energy, about $10^5$ FRB data can give constraint on $\beta$ tighter than the current cosmic microwave background data. In all the IDE models, about $10^6$ FRB data can constrain the absolute errors of $\beta$ to less than $0.10$, providing a way to precisely measure $\beta$ by only one cosmological probe. The reconstruction of the interaction term also shows that the FRB data could help constrain the redshift evolution of interaction.