# New constraints on varying α

@article{Rocha2003NewCO, title={New constraints on varying $\alpha$}, author={Graca M. Rocha and Richard Trotta and Carlos J. A. P. Martins and Alessandro Melchiorri and P. P. Avelino and Pedro T. P. Viana}, journal={New Astronomy Reviews}, year={2003}, volume={47}, pages={863-869} }

## 24 Citations

Early universe constraints on time variation of fundamental constants

- Physics
- 2008

We study the time variation of fundamental constants in the early Universe. Using data from primordial light nuclei abundances, cosmic microwave background, and the 2dFGRS power spectrum, we put…

Time variation of the fine structure constant in the early universe and the Bekenstein model

- Physics
- 2008

Aims. We calculate the bounds on the variation in the fine structure constant at the time of primordial nucleosynthesis and at the time of neutral hydrogen formation. We used these bounds and other…

Astronomical measurements and constraints on the variability of fundamental constants

- Physics
- 2007

We review the present status of how astronomical observations allow to constrain the evolution of fundamental constants of nature. The main observational constraints on the variation of the…

Primordial Nucleosynthesis with Varying Fundamental Constants: A Semianalytical Approach

- Physics
- 2006

Using the semianalytic method proposed by Esmailzadeh and coworkers we calculate the abundances of the light elements produced during primordial nucleosynthesis assuming that the gauge coupling…

The Fine-Structure Constant as a Probe of Chemical Evolution and Asymptotic Giant Branch Nucleosynthesis in Damped Lyα Systems

- Physics
- 2004

Evidence from a large sample of quasar absorption-line spectra in damped Lyα systems has suggested a possible time variation of the fine-structure constant, α. The most statistically significant…

Cosmological constants and variations

- Physics
- 2005

We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with…

Chaplygin gas and the cosmological evolution of alpha

- Physics
- 2009

The class of Chaplygin gas models regarded as a candidate of dark energy can be realized by a scalar field, which could drive the variation of the fine structure constant $\alpha$ during the cosmic…

Quintessence models and the cosmological evolution of α

- Physics
- 2004

The cosmological evolution of a quintessencelike scalar field {phi} coupled to matter and gauge fields leads to effective modifications of the coupling constants and particle masses over time. We…

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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…

Measuring $α$ in the Early Universe: CMB Temperature, Large-Scale Structure and Fisher Matrix Analysis

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- 2002

We extend our recent work on the effects of a time-varying fine-structure constant $\alpha$ in the cosmic microwave background, by providing a thorough analysis of the degeneracies between $\alpha$…

Further evidence for cosmological evolution of the fine structure constant.

- PhysicsPhysical review letters
- 2001

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.

Looking for a varying a in the cosmic microwave background

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We perform a likelihood analysis of the recently released BOOMERanG and MAXIMA data, allowing for the possibility of a time-varying fine-structure constant. We find that in general this data prefers…

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Any time variation in the fine-structure constant alters the ionization history of the universe and therefore changes the pattern of cosmic microwave background fluctuations. We calculate the changes…

Does the fine structure constant vary? A third quasar absorption sample consistent with varying α

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We report results from a third sample of quasar absorption line spectra from the Keck telescope which has been studied to search for any possible variation of the fine structure constant, α. This…

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This article describes the various experimental bounds on the variation of the fundamental constants of nature. After a discussion of the role of fundamental constants, their definition and link with…

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We have developed an improved recombination calculation of H, He I, and He II in the early universe that involves a line-by-line treatment of each atomic level. We find two major differences compared…

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The possible cosmological variation of the proton-to-electron mass ratio μ = mp/me was estimated by measuring the H2 wavelengths in the high-resolution spectrum of the quasar Q 0347-382. Our analysis…

Behavior of varying-alpha cosmologies

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- 2002

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,…