Local experiments see cosmologically varying constants

Shaw, Douglas J.; Barrow, John D.

doi:10.1016/j.physletb.2006.07.016

Cited by 31 publications

(18 citation statements)

References 34 publications

(44 reference statements)

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“…The first term represents the variation of the mean value of the constant on the orbit compared with its cosmological value. This shows that local terrestrial and Solar system experiments do measure the effects of the cosmological variation of the constants [123,457,458]. The second term is a seasonal modulation and it is usually parameterized [208] as…”

Section: Generalitiesmentioning

confidence: 99%

Varying Constants, Gravitation and Cosmology

Uzan

2011

Living Rev. Relativ.

740

784

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Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

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Section: Generalitiesmentioning

confidence: 99%

Varying Constants, Gravitation and Cosmology

Uzan

2011

Living Rev. Relativ.

740

784

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“…Such a linear approximation would be valid for uncoupled quintessence or sufficiently small -in this case the cosmon field acts as a ''cosmological clock.'' If the variation of fundamental couplings (such as the fine structure constant) can be written as a linear dependence on the displacement of , then their evolution inside the lump follows the cosmological evolution [42][43][44].…”

Section: Mass Freezingmentioning

confidence: 99%

Mass freezing in growing neutrino quintessence

2011

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Growing neutrino quintessence solves the coincidence problem for dark energy by a growing cosmological value of the neutrino mass which emerges from a cosmon-neutrino interaction stronger than gravity. The cosmon-mediated attraction between neutrinos induces the formation of large scale neutrino lumps in a recent cosmological epoch. We argue that the non-linearities in the cosmon field equations stop the further increase of the neutrino mass within sufficiently dense and large lumps. As a result, we find the neutrino induced gravitational potential to be substantially reduced when compared to linear extrapolations. We furthermore demonstrate that inside a lump the possible time variation of fundamental constants is much smaller than their cosmological evolution. This feature may reconcile current geophysical bounds with claimed cosmological variations of the fine structure constant.Comment: 15 pages, 12 figures. Version published in PR

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“…Theories with varying couplings, either at an effective or a fundamental level, are not a novelty in theoretical physics. Aside from sheer scientific curiosity, they find some justification in the fact that observations, both terrestrial and astronomical [8,9], do not exclude that the constants of Nature are, eventually, not really constant [10]. For instance, there exist constraints on the variation of the fine-structure constant, which depend on the time and spatial scale of the experiment [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Varying electric charge in multiscale spacetimes

2014

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We derive the covariant equations of motion for Maxwell field theory and electrodynamics in multiscale spacetimes with weighted Laplacian. An effective spacetime-dependent electric charge of geometric origin naturally emerges from the theory, thus giving rise to a varying fine-structure constant. The theory is compared with other varying-coupling models, such as those with a varying electric charge or varying speed of light. The theory is also confronted with cosmological observations, which can place constraints on the characteristic scales in the multifractional measure. We note that the model considered here is fundamentally different from those previously proposed in the literature, either of the varying-e or varying-c persuasion.

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Local experiments see cosmologically varying constants

Cited by 31 publications

References 34 publications

Varying Constants, Gravitation and Cosmology

Varying Constants, Gravitation and Cosmology

Mass freezing in growing neutrino quintessence

Varying electric charge in multiscale spacetimes

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