English

Cosmological application of the lens-redshift probability distribution with improved galaxy-scale gravitational lensing sample

Cosmology and Nongalactic Astrophysics 2023-05-01 v3 Astrophysics of Galaxies

Abstract

We conduct the cosmological analysis by using the lens-redshift distribution test with updated galaxy-scale strong lensing sample, where the considered scenarios involve three typical cosmological models (i.e., Λ\LambdaCDM, ω\omegaCDM and ω0ωa\omega_0\omega_aCDM models) and three typical choices (i.e., non-evolving, power-law and exponential forms) for the velocity-dispersion distribution function (VDF) of lens galaxies. It shows that degeneracies between cosmological and VDF parameters lead to the shifts of estimates on the parameters. The limits on Ωm0\Omega_{m0} from the lens-redshift distribution are consistent with those from the Pantheon+ Type Ia supernova (SN Ia) sample at 68.3% confidence level, though the uncertainties on Ωm0\Omega_{m0} from the former are about 3 to 8 times larger than those from the latter. The mean values of Ωm0\Omega_{m0} shift to the larger values in the power-law VDF case and to the lower values in the exponential VDF case, compared with those obtained in the non-evolving VDF case. In the ω\omegaCDM model, the limits on ω0\omega_0, i.e. the dark energy equation of state (EoS), are consistent with those from the Pantheon+ sample at 68.3% confidence level, but the mean values of ω0\omega_0 from the former are significantly smaller than those from the latter. In the ω0ωa\omega_0\omega_aCDM model, the uncertainties on ω0\omega_0 are dramatically enlarged compared with those obtained in the ω\omegaCDM model; moreover, the Markov chains of ωa\omega_a, i.e. the time-varying slope of EoS, do not achieve convergence in the three VDF cases. Overall, the lens-redshift distribution test is more effective on constraining Ωm0\Omega_{m0} than on the dark energy EoS.

Keywords

Cite

@article{arxiv.2304.06529,
  title  = {Cosmological application of the lens-redshift probability distribution with improved galaxy-scale gravitational lensing sample},
  author = {Hui Li and Yun Chen},
  journal= {arXiv preprint arXiv:2304.06529},
  year   = {2023}
}

Comments

10 pages, 3 figures, 1 table