Reappraisal of the limit on the variation in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>α</mml:mi></mml:math>implied by the Oklo natural fission reactors

Davis, E. D. D.; Hamdan, Leila J.

doi:10.1103/physrevc.92.014319

Cited by 13 publications

(11 citation statements)

References 106 publications

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“…In agreement with these laboratory experiments, the stability of α over the past 2 × 10 9 yr follows from the Oklo phenomenon -the uranium mine in Gabon, which provides the tightest terrestrial bound on α variation: α/α < 5 × 10 −18 yr −1 (Davis & Hamdan 2015). We note that the age 2 × 10 9 yr corresponds to the cosmological epoch at redshift z = 0.16 if a cosmology with H0 = 70 km s −1 Mpc −1 , ΩΛ = 0.7, and Ωm = 0.3 is adopted.…”

supporting

confidence: 71%

[C i], [C ii] and CO emission lines as a probe for α variations at low and high redshifts

Levshakov

Henkel

et al. 2017

Monthly Notices of the Royal Astronomical Society

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The offsets between the radial velocities of the rotational transitions of carbon monoxide and the fine structure transitions of neutral and singly ionized carbon are used to test the hypothetical variation of the fine structure constant, α. From the analysis of the [C i] and [C ii] fine structure lines and low J rotational lines of 12 CO and 13 CO, emitted by the dark cloud L1599B in the Milky Way disk, we find no evidence for fractional changes in α at the level of |∆α/α| < 3 × 10 −7 . For the neighbour galaxy M33 a stringent limit on ∆α/α is set from observations of three H ii zones in [C ii] and CO emission lines: |∆α/α| < 4 × 10 −7 . Five systems over the redshift interval z = 5.7 − 6.4, showing CO J = 6 − 5, J = 7 − 6 and [C ii] 158 µm emission, yield a limit on |∆α/α| < 1.3 × 10 −5 . Thus, a combination of the [C i], [C ii], and CO emission lines turns out to be a powerful tool for probing the stability of the fundamental physical constants over a wide range of redshifts not accessible to optical spectral measurements.

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supporting

confidence: 71%

[C i], [C ii] and CO emission lines as a probe for α variations at low and high redshifts

Levshakov

Henkel

et al. 2017

Monthly Notices of the Royal Astronomical Society

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“…In our analysis, we do not include geophysical constraints on the variation in α, coming from the Oklo natural nuclear reactor (Fujii et al 2002;Davis & Hamdan 2015) and meteoric data (Olive et al 2004). This is motivated by the model dependence of such data, as they only provide stringent constraints on α if one assumes that only the fine-structure constant can vary while the strong sector of the theory is unchanged, which is a simplistic assumption for constraints that stem from nuclear-physics processes (Martins 2017).…”

Section: Currently Available Data For α Variationmentioning

confidence: 99%

Euclid: Constraining dark energy coupled to electromagnetism using astrophysical and laboratory data

Martinelli

Martins

Nesseris

et al. 2021

A&A

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In physically realistic, scalar-field-based dynamical dark energy models (including, e.g., quintessence), one naturally expects the scalar field to couple to the rest of the model’s degrees of freedom. In particular, a coupling to the electromagnetic sector leads to a time (redshift) dependence in the fine-structure constant and a violation of the weak equivalence principle. Here we extend the previous Euclid forecast constraints on dark energy models to this enlarged (but physically more realistic) parameter space, and forecast how well Euclid, together with high-resolution spectroscopic data and local experiments, can constrain these models. Our analysis combines simulated Euclid data products with astrophysical measurements of the fine-structure constant, α, and local experimental constraints, and it includes both parametric and non-parametric methods. For the astrophysical measurements of α, we consider both the currently available data and a simulated dataset representative of Extremely Large Telescope measurements that are expected to be available in the 2030s. Our parametric analysis shows that in the latter case, the inclusion of astrophysical and local data improves the Euclid dark energy figure of merit by between 8% and 26%, depending on the correct fiducial model, with the improvements being larger in the null case where the fiducial coupling to the electromagnetic sector is vanishing. These improvements would be smaller with the current astrophysical data. Moreover, we illustrate how a genetic algorithms based reconstruction provides a null test for the presence of the coupling. Our results highlight the importance of complementing surveys like Euclid with external data products, in order to accurately test the wider parameter spaces of physically motivated paradigms.

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“…Several authors have analyzed the Oklo data to put constraints on the possible variation of the fundamental constants (Petrov et al 2006;Davis & Hamdan 2015). The most stringent limit was established by Davis & Hamdan (2015):…”

Section: The Oklo Phenomenonmentioning

confidence: 99%

Variation of fundamental constants and white dwarfs

Landau

2019

Proc. IAU

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Theories that attempt to unify the four fundamental interactions and alternative theories of gravity predict time and/or spatial variation of the fundamental constants of nature. Different versions of these theories predict different behaviours for these variations. As a consequence, experimental and observational bounds are an important tool to check the validity of such proposals. In this paper, we review constraints on the possible variation of the fundamental constants from astronomical observations and geophysical experiments designed to test the constancy of the fundamental constants of nature over different timescales. We also focus on the limits that can be obtained from white dwarfs, which can constrain the variation of the constants with the gravitational potential.

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Reappraisal of the limit on the variation inαimplied by the Oklo natural fission reactors

Abstract: Background: A signature of many dynamical models of dark energy is that they admit variation in the fine structure constant α over cosmological time scales.

Cited by 13 publications

References 106 publications

[C i], [C ii] and CO emission lines as a probe for α variations at low and high redshifts

[C i], [C ii] and CO emission lines as a probe for α variations at low and high redshifts

Euclid: Constraining dark energy coupled to electromagnetism using astrophysical and laboratory data

Variation of fundamental constants and white dwarfs

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