SIMBAD references

Exotic cosmologies predict the variability of the fundamental physical constants over the cosmic time. Using the Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph (VLT/UVES) high-resolution spectra of the quasar Q0347-3819 and unblended electronic-vibrational-rotational lines of the H₂ molecule identified at z_abs=3.025 we test possible changes in the proton-to-electron mass ratio µ₀=m_p/m_e over the period of ∼11Gyr. We obtained a new constraint on the time-averaged variation rate of µ₀ of |µ{dot}/µ₀ |<5x10^–15.yr^–1 (1σ confidence level). The estimated 1σ uncertainty interval of the |Δµ/µ₀ | ratio of about 0.004 per cent implies that since the time when the H₂ spectrum was formed at z_abs=3.025, µ₀ has not changed by more than a few thousandths of a per cent.