On the stability of fundamental couplings in the Galaxy

M., João, Simão; Martins, C. J. A. P.; Mota, Inês N. R.; Vianez, P. M. T.

doi:10.1016/j.physletb.2015.08.018

Cited by 4 publications

(3 citation statements)

References 19 publications

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“…Finally, we should point out that the radio band sensitivity is even better for measurements within the Galaxy (thus effectively at z = 0), where one can search for environ mental dependencies since measurements can be made in regions with densities that are many orders of magnitude smaller than the local one. Here again there is no current evidence for variations, up to a sensitivity at the 0.05 ppm level for μ [107] and at the 0.1 ppm level for α [108]. Searches for environmental dependencies can also be done using compact astrophysical objects, to be briefly discussed in the next section.…”

Section: Spatial Variations?mentioning

confidence: 99%

The status of varying constants: a review of the physics, searches and implications

2017

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Abstract. The observational evidence for the recent acceleration of the universe demonstrates that canonical theories of cosmology and particle physics are incomplete-if not incorrect-and that new physics is out there, waiting to be discovered. A key task for the next generation of laboratory and astrophysical facilities is to search for, identify and ultimately characterize this new physics. Here we highlight recent developments in tests of the stability of nature's fundamental couplings, which provide a direct handle on new physics: a detection of variations will be revolutionary, but even improved null results provide competitive constraints on a range of cosmological and particle physics paradigms. A joint analysis of all currently available data shows a preference for variations of α and µ at about the two-sigma level, but inconsistencies between different sub-sets (likely due to hidden systematics) suggest that these statistical preferences need to be taken with caution. On the other hand, these measurements strongly constrain Weak Equivalence Principle violations. Plans and forecasts for forthcoming studies with facilities such as ALMA, ESPRESSO and the ELT, which should clarify these issues, are also discussed, and synergies with other probes are briefly highlighted. The goal is to show how a new generation of precision consistency tests of the standard paradigm will soon become possible.PACS numbers: 98.80.Es, 95.36.+x, 98.62.Ra,

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Section: Spatial Variations?mentioning

confidence: 99%

The status of varying constants: a review of the physics, searches and implications

2017

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“…On the other hand, in our analysis we restrict ourselves to considering possible time variations of the fundamental couplings (corresponding to redshift dependencies in an astrophysical context). We will not consider the possibility of spatial (or environmental) dependencies; some constraints on such scenarios can be obtained using measurements of these constants within the Galaxy [22].…”

Section: Introductionmentioning

confidence: 99%

Consistency of local and astrophysical tests of the stability of fundamental constants

Martins

Miñana

2019

Physics of the Dark Universe

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Tests of the stability of nature's fundamental constants are one of the cornerstones of the ongoing search for the new physics which is required to explain the recent acceleration of the universe. The two main settings for these tests are high-resolution spectroscopy of astrophysical systems (mainly in low-density absorption clouds along the line of sight of bright quasars) and laboratory comparisons of pairs of atomic clocks. Here we use standard chisquare techniques to perform a global analysis of all currently available data, studying both the consistency of tests of stability of different constants (specifically the fine-structure constant α, the proton-to-electron mass ratio µ and the proton gyromagnetic ratio g p ) and the consistency between local laboratory and astrophysical tests. We start by doing a model-independent analysis (studying the internal consistency of the various available datasets) but also explore specific phenomenological models motivated by string theory and grand unification. Overall there is weak (one to two sigma) evidence of variations, at the level of up to a few parts per million, and reasonable agreement between laboratory and astrophysical tests. This result holds even if one removes from the analysis the Webb et al. archival dataset of α measurements. Forthcoming astrophysical facilities, such as the ESPRESSO spectrograph, should be able to confirm or rule out these hints.

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“…Due to the impressive progress in recent years, optical clocks are deemed for the redefinition of SI second in future as they have surpassed the performance of Cs primary clocks in both accuracy and stability [1][2][3][4][5] . At the same time, these ultra-precise optical clocks offer new possibilities for high precision tests of fundamental physics [6][7][8][9] , geophysics [10; 11] , improved timekeeping and satellites navigation [12; 13] . On the other hand, a more accurate and direct mean of optical frequency comparison is required for today's best clocks over quite long distance.…”

Section: Introductionmentioning

confidence: 99%

A compact, transportable single-ion optical clock with 7.8 × 10−17 systematic uncertainty

et al. 2017

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A transportable optical clock refer to the 4s 2 S 1/2 -3d 2 D 5/2 electric quadrupole transition at 729 nm of single 40 Ca + trapped in mini Paul trap has been developed. The physical system of 40 Ca + optical clock is re-engineered from a bulky and complex setup to an integration of two subsystems: a compact single ion unit including ion trapping and detection modules, and a compact laser unit including laser sources, beam distributor and frequency reference modules. Apart from the electronics, the whole equipment has been constructed within a volume of 0.54 m 3 . The systematic fractional uncertainty has been evaluated to be 7.7×10 -17 , and the Allan deviation fits to be 14 2.3 10    by clock self-comparison with a probe pulse time 20 ms.

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On the stability of fundamental couplings in the Galaxy

Cited by 4 publications

References 19 publications

The status of varying constants: a review of the physics, searches and implications

The status of varying constants: a review of the physics, searches and implications

Consistency of local and astrophysical tests of the stability of fundamental constants

A compact, transportable single-ion optical clock with 7.8 × 10−17 systematic uncertainty

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