Publication Date:
2013-08-18
Description:
We obtain constraints on the variation of the fundamental constants from the full shape of the redshift–space correlation function of a sample of luminous galaxies drawn from the Data Release 9 of the Baryonic Oscillations Spectroscopic Survey. We combine this information with additional data from recent cosmic microwave background, baryon acoustic oscillations and H 0 measurements. We focus on possible variations of the fine structure constant α and the electron mass m e in the early Universe, and study the degeneracies between these constants and other cosmological parameters, such as the dark energy equation of state parameter w DE , the massive neutrinos fraction f , the effective number of relativistic species N eff and the primordial helium abundance Y He . In the case when only one of the fundamental constants is varied, our final bounds are $\alpha / \alpha _0 = 0.9957_{-0.0042}^{+0.0041}$ and $m_{\rm e} /(m_{\rm e})_0 = 1.006_{-0.013}^{+0.014}$ . For the joint variation of both fundamental constants, our results are $\alpha / \alpha _0 = 0.9901_{-0.0054}^{+0.0055}$ and m e /( m e ) 0 = 1.028 ± 0.019. The variations of α and m e from their present values affect the bounds on other cosmological parameters. Although when m e is allowed to vary our constraints on w DE are consistent with a cosmological constant, when α is treated as a free parameter we find w DE = –1.20 ± 0.13; more than 1 away from its standard value. When f and α are allowed to vary simultaneously, we find f 〈 0.043 (95 per cent confidence level, CL), implying a limit of m 〈 0.46 eV (95 per cent CL), while for m e variation, we obtain f 〈 0.086 (95 per cent CL), which implies m 〈 1.1 eV (95 per cent CL). When N eff or Y He are considered as free parameters, their simultaneous variation with α provides constraints close to their standard values (when the H 0 prior is not included in the analysis), while when m e is allowed to vary, their preferred values are significantly higher. In all cases, our results are consistent with no variations of α or m e at the 1 or 2 level.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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