Related papers: Loop Quantum Cosmology and the Fine Structure Cons…
We examine the evolution of a closed, homogeneous and anisotropic cosmology subject to a variation of the fine structure 'constant', \alpha, within the context of the theory introduced by Bekenstein, Sandvik, Barrow and Magueijo, which…
We introduce a model which allows the fine structure constant (alpha) to vary throughout space and time due to a coupling to a scalar field with a non-canonical kinetic structure. This provided a new extension of the…
We work with a class of scalar extended theory of gravity that can drive the present cosmic acceleration as well as accommodate a mild cosmic variation of the fine structure constant $\alpha$. The motivation comes from a vintage theory…
A phenomenological model is proposed to explain the recent observed cosmological variation of the fine structure constant as an effect of the quantum vacuum, assuming a flat universe with cosmological constant $\Lambda$ in the cases…
We briefly review the recent experimental results on possible variations of the fine structure constant $\alpha$ on the cosmological time scale and its position dependence. We outline the theoretical grounds for the assumption that $\alpha$…
If the fine structure constant $\alpha =e^2/(\hbar c)$ were to change, then a number of interpretations would be possible, attributing this change either to variations in the electron charge, the dielectric constant of the vacuum, the speed…
We study the change of the effective fine structure constant in the cosmological models of a scalar field with a non-vanishing coupling to the electromagnetic field. Combining cosmological data and terrestrial observations we place…
Cosmological variation of the fine structure constant $\alpha$ due to the evolution of a spatially homogeneous ultra-light scalar field ($m \sim H_0$) during the matter and $\Lambda$ dominated eras is analyzed. Agreement of $\Delta…
We study the cosmological evolution of the fine structure constant, $\alpha$, and the proton-to-electron mass ratio, $\mu=m_p/m_e$, in the context of a generic class of models where the gauge kinetic function is a linear function of a…
Bekenstein's model of a scalar field, \phi, that affects the electromagnetic permeability (usually identified with ``changing \alpha'') predicts tiny variations of the effective fine structure constant up to very high red-shifts,…
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 investigate the cosmological consequences of a simple theory in which the electric charge $e$ is allowed to vary. The theory is locally gauge and Lorentz invariant, and satisfies general covariance. We find that in this theory the fine…
Motivated by reported claims of the measurements of a variation of the fine structure constant $\alpha$ we consider a theory where the electric charge, and consequently $\alpha$, is not a constant but depends on the Ricci scalar $R$. %We…
In the present work, we consider the cosmological constant model $\Lambda\propto\alpha^{-6}$, which is well motivated from three independent approaches. As is well known, the hint of varying fine structure constant $\alpha$ was found in…
Calculation of the Dirac hydrogen atom spectrum in the framework of dynamical fine structure constant (alpha) variability discloses a small departure in the laboratory from Sommerfeld's formula for the fine structure shifts, possibly…
The recent evidence for a cosmological evolution of the fine structure constant \alpha=e^2/\hbar c found from an analysis of absorption systems in the spectra of distant quasars, is modelled by a cosmological scenario in which it is assumed…
Recent theoretical ideas and observational claims suggest that the fine structure constant alpha may be variable. We examine a spectrum of models in which alpha is a function of a scalar field. Specifically, we consider three scenarios:…
We start with a brief account of the latest analysis of the Oklo phenomenon providing the still most stringent constraint on time-variability of the fine- structure constant $\alpha$. Comparing this with the recent result from the…
This thesis describes a detailed investigation of the effects of matter inhomogeneities on the cosmological evolution of the fine structure constant using the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) theory. We briefly review the…
We review properties of cosmological theories for the variation of the fine structure 'constant'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that are…