Related papers: Constraining the Variation in Fine-Structure Const…

Large statistical samples of quasar spectra have previously indicated possible cosmological variations in the fine-structure constant, $\alpha$. A smaller sample of higher signal-to-noise ratio spectra, with dedicated calibration, would…

We study constraints on time variation of the fine structure constant alpha from cosmic microwave background (CMB) taking into account simultaneous change in alpha and the electron mass m_e which might be implied in unification theories. We…

Various classes of exotic singularity models have been studied as possible mimic models for the observed recent acceleration of the universe. Here we further study one of these classes and, under the assumption that they are…

Dynamical models of dark energy can imply that the fine structure constant $\alpha$ varies over cosmological time scales. Data on shifts in resonance energies $E_r$ from the Oklo natural fission reactor have been used to place restrictive…

The strong intervening absorption system at redshift 1.15 towards the very bright quasar HE 0515$-$4414 is the most studied absorber for measuring possible cosmological variations in the fine-structure constant, $\alpha$. We observed HE…

This paper presents the constraints on the time variation of the fine structure constant at recombination relative to its present value, Delta_alpha = (alpha_rec-alpha_0) / alpha_0, obtained from the analysis of the WMAP-3yr Cosmic…

Motivated by previous studies of QSO spectra that reported a variation of the fine structure constant alpha, a search for C IV and Si IV doublets was conducted in the absorption spectrum toward QSO 1101-264, obtained by VLT-UVES during the…

We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current…

I review recent constraints on and claimed detections of a time-varying fine-structure constant $\alpha$. Our results are consistent with no variation in $\alpha$ from the epoch of recombination to the present day, and restrict any such…

Nine quasar absorption spectra at 21-cm and UV rest-wavelengths are used to estimate possible variations in x=alpha^2 g_p mu, (alpha is the fine structure constant, g_p the proton g-factor and mu=me/mp the electron-to-proton mass ratio). We…

QSO absorption spectra provide an extremely useful probe of possible cosmological variation in various physical constants. Comparison of H I 21cm absorption with corresponding molecular (rotational) absorption spectra allows us to constrain…

We update the constraints on the time variation of the fine structure constant $\alpha$ and the electron mass $m_e$, using the latest CMB data, including the 7-yr release of WMAP. We made statistical analyses of the variation of each one of…

Detecting or placing upper limits on spacetime variations of fundamental constants requires quantifying every potential source of uncertainty. We continue our previous study into the impact of continuum variations on measurements of the…

We put bounds on the variation of the value of the fine structure constant $\alpha$, at the time of Big Bang nucleosynthesis. We study carefully all light elements up to $^7$Li. We correct a previous upper limit on $|\Delta \alpha /…

Any variation of the fundamental physical constants, and more particularly of the fine structure constant, $\alpha$, or of the mass of the electron, $m_e$, would affect the recombination history of the Universe and cause an imprint on the…

Recent experimental data indicates that the fine structure constant alpha may be varying on cosmological time scales. We consider the possibility that such a variation could be induced by a second order phase transition which occurs at late…

We review the observational information on the constancy of the fine structure constant alpha. We find that small improvements on the measurement of ^{187}Re lifetime can provide significant progress in exploring the range of variability…

In order to probe a possible time variation of the fine-structure constant ($\alpha$), we propose a new method based on Strong Gravitational Lensing and Type Ia Supernovae observations. By considering a class of dilaton runaway models,…

We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure…

We report the detection of the satellite 18 cm OH lines at 1612 and 1720 MHz in the z=0.2467 molecular absorption system toward the radio source PKS 1413+135. The two OH lines are conjugate; the 1612 MHz line is seen in absorption while the…