Abstract. An Eötvös experiment to test the weak equivalence principle (WEP) for zero-point vacuum energy is proposed using a satellite. Following the suggestion of Ross for a terrestrial experiment of this type, the acceleration of a spherical test mass of aluminium would be compared with that of a similar test mass made from another material. The estimated ratio of the zero-point vacuum energy density inside the aluminium sphere to the rest mass energy density is ~1.6×10^-14, which would allow a 1% resolution of a potential WEP violation observed in a satellite mission test that had a baseline sensitivity to WEP violations of ~10^-16. An observed violation of the WEP for vacuum energy density would constitute a significant clue as to the origin of the cosmological constant and the source of dark energy, and test a recently proposed resolution of the cosmological constant problem, based on a model of nonlocal quantum gravity and quantum field theory.

Received 13 August 2002
Published 14 November 2002