The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: constraints on the time variation of fundamental constants from the large-scale two-point correlation function

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 H₀ 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_ν, 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 α / α _0 = 0.9957_{-0.0042}^{+0.0041} and m_e /(m_e)_0 = 1.006_{-0.013}^{+0.014}. For the joint variation of both fundamental constants, our results are α / α _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 1σ away from its standard value. When f_ν and α are allowed to vary simultaneously, we find f_ν < 0.043 (95 per cent confidence level, CL), implying a limit of ∑m_ν < 0.46 eV (95 per cent CL), while for m_e variation, we obtain f_ν < 0.086 (95 per cent CL), which implies ∑m_ν < 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 H₀ 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 1σ or 2σ level.