Is there further evidence for spatial variation of fundamental constants?

Berengut, J. C.; Flambaum, V. V.; King, Julian A.; Curran, S. J.; Webb, John R.

doi:10.1103/physrevd.83.123506

Cited by 42 publications

(55 citation statements)

References 46 publications

(81 reference statements)

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“…Other analyses have confirmed these results [3,4], although the inclusion of more recent measurements reduces the allowed amplitude by about twenty percent [5], to a maximum of about 8 parts per million (with no significant changes to the preferred direction). Although it is clear that some systematic effects are present in the archival data [6], it is presently unclear if they could explain the above results [7,8].…”

Section: Introductionsupporting

confidence: 56%

Constraining spatial variations of the fine structure constant using clusters of galaxies and Planck data

et al. 2016

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We propose an improved methodology to constrain spatial variations of the fine structure constant using clusters of galaxies. We use the Planck 2013 data to measure the thermal Sunyaev-Zeldovich effect at the location of 618 X-ray selected clusters. We then use a Monte Carlo Markov Chain algorithm to obtain the temperature of the Cosmic Microwave Background at the location of each galaxy cluster. When fitting three different phenomenological parameterizations allowing for monopole and dipole amplitudes in the value of the fine structure constant we improve the results of earlier analysis involving clusters and the CMB power spectrum, and we also found that the best-fit direction of a hypothetical dipole is compatible with the direction of other known anomalies. Although the constraining power of our current datasets do not allow us to test the indications of a fine-structure constant dipole obtained though high-resolution optical/UV spectroscopy, our results do highlight that clusters of galaxies will be a very powerful tool to probe fundamental physics at low redshift.

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Section: Introductionsupporting

confidence: 56%

Constraining spatial variations of the fine structure constant using clusters of galaxies and Planck data

et al. 2016

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“…So far, none are found which are likely to emulate the apparent cosmological dipole in α we detect. Consistency with other astronomical data is discussed in [14]. Consistency with laboratory, meteorite, and Oklo natural reactor is discussed in [15].…”

Section: Fig 2 ∆α/α For the Combined Keck And Vlt Data Vs Anglementioning

confidence: 99%

Indications of a Spatial Variation of the Fine Structure Constant

et al. 2011

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We previously reported Keck telescope observations suggesting a smaller value of the fine structure constant, α, at high redshift. New Very Large Telescope (VLT) data, probing a different direction in the universe, shows an inverse evolution; α increases at high redshift. Although the pattern could be due to as yet undetected systematic effects, with the systematics as presently understood the combined dataset fits a spatial dipole, significant at the 4.2σ level, in the direction right ascension 17.5±0.9 hours, declination −58±9 degrees. The independent VLT and Keck samples give consistent dipole directions and amplitudes, as do high and low redshift samples. A search for systematics, using observations duplicated at both telescopes, reveals none so far which emulate this result.PACS numbers: 06.20. Jr, 95.30.Dr, 95.30.Sf, 98.62.Ra, 98.80.Es, 98.80.Jk Quasar spectroscopy as a test of fundamental physics.-The vast light-travel times to distant quasars allow us to probe physics at high redshift. The relative wavenumbers, ω z , of atomic transitions detected at redshift z = λ obs /λ lab − 1, can be compared with laboratory values, ω 0 , via the relationshipwhere the coefficient Q measures the sensitivity of a given transition to a change in α. The variation in both magnitude and sign of Q for different transitions is a significant advantage of the Many Multiplet method [1, 2], helping to combat potential systematics.The first application of this method, 30 measurements of ∆α/α = (α z − α 0 ) /α 0 , indicated a smaller α at high redshift at the 3σ significance level. By 2004 we had made 143 measurements of α covering a wide redshift range, using further data from the Keck telescope obtained by 3 separate groups, supporting our earlier findings, that towards that general direction in the universe at least, α may have been smaller at high redshift, at the 5σ level [3][4][5]. The constant factor at that point was (undesirably) the telescope and spectrograph.New data from the VLT.-We have now analysed a large dataset from a different observatory, the VLT. Full details and searches for systematic errors will be given elsewhere [6,7]. Here we summarize the evidence for spatial variation in α emerging from the combined Keck+VLT samples. Quasar spectra, obtained from the ESO Science Archive, were selected, prioritising primarily by expected signal to noise but with some preference given to higher redshift objects and to objects giving more extensive sky coverage. The ESO midas pipeline was used for the first data reduction step, including wavelength calibration, although enhancements were made to derive a more robust and accurate wavelength solution from an improved selection of thorium-argon calibration lamp emission lines [8]. Echelle spectral orders from several exposures of a given quasar were combined using uves popler [9]. A total of 60 quasar spectra from the VLT have been used for the present work, yielding 153 absorption systems. Absorption systems were identified via a careful visual search of each spectrum, us...

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“…King et al (2012) have re-analyzed the VLT and Keck Observatory data and found a non-null spatial variation of α, and that the dipole model is preferred over the monopole model. Berengut et al (2011) have demonstrated that it is possible to set constraints on the spatial variation of the fine structure constant using Big Bang nucleosynthesis (BBN) primordial abundances, though the existing data on it do not support the dipole interpretation. A geophysical analysis to test the spatial variation of α was performed by Berengut & Flambaum (2012).…”

Section: Introductionmentioning

confidence: 99%

New cosmological constraints on the variation of fundamental constants: the fine structure constant and the Higgs vacuum expectation value

Mosquera

Civitarese

2013

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Aims. We study the time variation of the fine structure constant, α, and the Higgs vacuum expectation value v, during the Big Bang nucleosynthesis (BBN). Methods. We computed primordial abundances of light nuclei produced during the BBN stage by including resonances in the leading reaction rates which reduce the primordial abundance of beryllium. We performed this calculation considering that α and v may vary during the BBN. Using observable data on deuterium, 4 He, and 7 Li, we set constraints on the variation of the fundamental constants. Results. Results indicate a null variation of α and v, while the best-fit value for the baryon-to-photon ratio agrees well with the WMAP value. Conclusions. We found that the variation of α is null within 3σ, the variation of v is null within 6σ, and the preferred value of the baryon-to-photon ratio is in good agreement, within 3σ, with the value extracted using the WMAP data. We improve the fits respect to previous works.

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Is there further evidence for spatial variation of fundamental constants?

Cited by 42 publications

References 46 publications

Constraining spatial variations of the fine structure constant using clusters of galaxies and Planck data

Constraining spatial variations of the fine structure constant using clusters of galaxies and Planck data

Indications of a Spatial Variation of the Fine Structure Constant

New cosmological constraints on the variation of fundamental constants: the fine structure constant and the Higgs vacuum expectation value

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