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A paper written by Authors: Rong-Jia Yang, Shuang Nan Zhang, published in Mon. Not. R. Astron. Soc. 000, 1–7 (2009) and modified on today's Physics ArXiv asks a question we have looked at before on PF, "Is there an age problem in the early universe of the [itex]\Lambda[/itex]CDM model?"
At high red shift some objects are observed that appear to be older than the universe in that epoch. In the previous thread linked to above we considered APM 08279+5255 and then (2005) concluded further work needs to be done to reassess its age. Yang and Zhang's paper does just this using WMAP5 data and seem to have hardened the problem.
From the paper's conclusion:
Garth
At high red shift some objects are observed that appear to be older than the universe in that epoch. In the previous thread linked to above we considered APM 08279+5255 and then (2005) concluded further work needs to be done to reassess its age. Yang and Zhang's paper does just this using WMAP5 data and seem to have hardened the problem.
From the paper's conclusion:
The only way to reconcile the elapsed time T of APM08279+5255 with the age of the Universe at z = 3.91 in the [itex]\Lambda[/itex]CDM model, is to take very small values of H0 and [itex]\Omega[/itex]m, which certainly contradict many other independent observations. We therefore conclude that the [itex]\Lambda[/itex]CDM model suffers from a problem with the estimated age of APM 08279+5255 at redshift z = 3.91, based on the currently best available data for the Hubble constant Hsub]0[/sub] and the matter density [itex]\Omega[/itex]m (recently Riess et al. (2009) obtained H0 = 74.2 ± 3.6 km s−1Mpc−1, which may lead to more serious age problem in [itex]\Lambda[/itex]CDM model). These results can be tested with future cosmological observations. Of course, new and more reliable determination of the age of APM 08279+5255 are also needed.
Garth
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