Spatial variation of fundamental couplings and Lunar Laser Ranging

Abstract

If the fundamental constants of nature have a cosmic spatial variation, there will in general be extra forces with a preferred direction in space which violate the equivalence principle. We show that the millimeter-precision Apache Point Observatory Lunar Laser-ranging Operation provides a very sensitive probe of such variation that has the capability of detecting a cosmic gradient of the ratio between the quark masses and the strong interaction scale at the level with the gradient of ln (m_quark/Lambda_QCD) ~ 2.6 x 10^-6 Glyr^-1, which is comparable to the cosmic gradients suggested by the recently reported measurements of Webb et al. We also point out the capability of presently planned improved equivalence principle tests, at the Delta g/g < 10^-17 level, to probe similar cosmic gradients.

9 pages

References in corpus (5)

• Test of the Equivalence Principle Using a Rotating Torsion Balance
• Testing General Relativity with Atom Interferometry
• Equivalence Principle Violations and Couplings of a Light Dilaton
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• Is there further evidence for spatial variation of fundamental constants?

Cited by in corpus (7)

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• Constraining the fundamental interactions and couplings with Eötvös experiments
• Orbital effects of spatial variations of fundamental coupling constants
• A uniform treatment of the orbital effects due to a violation of the Strong Equivalence Principle in the gravitational Stark-like limit