English

Testing the (generalized) Chaplygin gas model with the Lookback time-Redshift data

Cosmology and Nongalactic Astrophysics 2009-09-11 v2 General Relativity and Quantum Cosmology

Abstract

The Chaplygin gas (CG) and the generalized Chaplygin gas (GCG) models, proposed as candidates of the unified dark matter-dark energy (UDME), are tested with the look-back time (LT) redshift data. We find that the LT data only give a very weak constraint on the model parameter. However, by combing the LT with the baryonic acoustic oscillation peak, we obtain, at the 95.4% confidence level, 0.68Ac0.820.68\leq A_c\leq0.82 and 0.59h0.650.59\leq h\leq0.65 for the CG model, and 0.67As0.890.67\leq A_s\leq0.89 and 0.29α0.61-0.29\leq \alpha\leq0.61 for the GCG model. This shows that both the CG and the GCG are viable as a candidate of UDME. Within the GCG model, we also find that the Chaplygin gas model (α=1\alpha=1) is ruled out by these data at the 99.7% confidence level.

Cite

@article{arxiv.0908.3415,
  title  = {Testing the (generalized) Chaplygin gas model with the Lookback time-Redshift data},
  author = {Zhengxiang Li and Puxun Wu and Hongwei Yu},
  journal= {arXiv preprint arXiv:0908.3415},
  year   = {2009}
}

Comments

13 pages, 5 figures, a couple of references added, published version

R2 v1 2026-06-21T13:38:21.758Z