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arXiv · 0908.3415

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

Zhengxiang Li·Puxun Wu·Hongwei Yu
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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, $0.68\leq A_c\leq0.82$ and $0.59\leq h\leq0.65$ for the CG model, and $0.67\leq A_s\leq0.89$ and $-0.29\leq α\leq0.61$ 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 ($α=1$) is ruled out by these data at the 99.7% confidence level.

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Zhengxiang Li, Puxun Wu, Hongwei Yu. 2009-09-11. Testing the (generalized) Chaplygin gas model with the Lookback time-Redshift data. https://doi.org/10.1088/1475-7516/2009/09/017

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