Varying alpha in a more realistic Universe

@article{Mota2004VaryingAI,
  title={Varying alpha in a more realistic Universe},
  author={David F. Mota and John D. Barrow},
  journal={Physics Letters B},
  year={2004},
  volume={581},
  pages={141-146}
}
Abstract We study the space–time evolution of the fine structure constant, α , inside evolving spherical overdensities in a lambda-CDM Friedmann universe using the spherical infall model. We show that its value inside virialised regions will be significantly larger than in the low-density background universe. The consideration of the inhomogeneous evolution of the universe is therefore essential for a correct comparison of extragalactic and solar system limits on, and observations of, possible… 

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References

SHOWING 1-10 OF 31 REFERENCES
A simple cosmology with a varying fine structure constant.
TLDR
This model satisfies geonuclear, nucleosynthesis, and cosmic microwave background constraints on time variation in alpha, while fitting the observed accelerating Universe and evidence for small alpha variations in quasar spectra and specific restrictions on the nature of the dark matter.
Variations of alpha in space and time
We study inhomogeneous cosmological variations in the fine structure 'constant', $\alpha ,$ in Friedmann universes. Inhomogeneous motions of the scalar field driving changes in $\alpha $ display
Early universe constraints on a time varying fine structure constant
Higher-dimensional theories have the remarkable feature of predicting a time (and hence redshift) dependence of the `fundamental' four dimensional constants on cosmological timescales. In this paper
Further evidence for cosmological evolution of the fine structure constant.
TLDR
The results of a search for time variability of the fine structure constant alpha using absorption systems in the spectra of distant quasars find no systematic effects which can explain the results.
Gauge-invariant perturbations of varying-alpha cosmologies
Using a gauge-invariant formalism we derive and solve the perturbed cosmological equations for the BSBM theory of varying fine structure 'constant'. We calculate the time evolution of inhomogeneous
Qualitative analysis of universes with varying alpha
Assuming a Friedmann universe which evolves with a power-law scale factor, a = t n, we analyse the phase space of the system of equations that describes a time-varying fine structure 'constant', α,
Spatial variations of fundamental constants
We show that observational limits on the possible time variation of constants of Nature are significantly affected by allowing for both space and time variation. Bekenstein's generalisation of
The cosmological evolution of the nucleon mass and the electroweak coupling constants
Abstract. Starting from astrophysical indications that the fine structure constant might undergo a small cosmological time shift, we discuss the implications of such an effect from the point of view
Anthropic Reasons for Non-Zero Flatness and Lambda
In some cosmological theories with varying constants there are anthropic reasons why the expansion of the universe must not be too {\it close} to flatness or the cosmological constant too close to
Behavior of varying-alpha cosmologies
We determine the behaviour of a time-varying fine structure 'constant' $\alpha (t)$ during the early and late phases of universes dominated by the kinetic energy of changing $\alpha (t)$, radiation,
...
1
2
3
4
...