Publication Date:
2015-08-04
Description:
By detecting redshift drift in the spectra of the Lyman- \(\alpha \) forest of distant quasars, the Sandage–Loeb (SL) test directly measures the expansion of the universe, covering the “redshift desert” of \(2 \lesssim z \lesssim 5\) . Thus this method is definitely an important supplement to the other geometric measurements and will play a crucial role in cosmological constraints. In this paper, we quantify the ability of the SL test signal by a CODEX-like spectrograph for constraining interacting dark energy. Four typical interacting dark energy models are considered: (i) \(Q=\gamma H\rho _c\) , (ii) \(Q=\gamma H\rho _{de}\) , (iii) \(Q=\gamma H_0\rho _c\) , and (iv) \(Q=\gamma H_0\rho _{de}\) . The results show that for all the considered interacting dark energy models, relative to the current joint SN \(+\) BAO \(+\) CMB \(+\) \(H_0\) observations, the constraints on \(\Omega _m\) and \(H_0\) would be improved by about 60 and 30–40 %, while the constraints on w and \(\gamma \) would be slightly improved, with a 30-year observation of the SL test. We also explore the impact of the SL test on future joint geometric observations. In this analysis, we take the model with \(Q=\gamma H\rho _c\) as an example, and we simulate future SN and BAO data based on the space-based project WFIRST. We find that with the future geometric constraints, the redshift drift observations would help break the geometric degeneracies in a meaningful way, thus the measurement precisions of \(\Omega _m\) , \(H_0\) , w , and \(\gamma \) could be substantially improved using future probes.
Print ISSN:
1434-6044
Electronic ISSN:
1434-6052
Topics:
Physics
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