Dark Energy Constraints from Espresso Tests of the Stability of Fundamental Couplings

Stringent limit on space-time variation of fine-structure constant using high-resolution of quasar spectra

We have obtained a new limit on the space-time variation of the fine-structure constant(α=e24πε0ℏc)using the observations of Mg II line in quasar J110325-264515 spectra with redshiftzabs=1.8389. The obtained parameter isΔα/α=(−0.155±0.728)×10−6. It was derived from the comparison between the quasar J110325-264515 spectra and the laboratory sample spectra. The obtained result appears as a new highly sensitive probe of the cosmological variability of the fine-structure constant. From the relative spectra of the Mg II, we found the most stringent constraint up today onΔα/αcomparing to the previously published results.

New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.