Conservation Laws and Preferred Frames in Relativistic Gravity. II. Experimental Evidence to Rule Out Preferred-Frame Theories of Gravity

Abstract

Some metric theories of gravity single out the mean rest-frame of the Universe as a "preferred frame." They include theories devised by Page and Tupper, Yilmaz, Papapetrou, Ni, Coleman, and Rosen, as well as a vector-metric theory studied in Paper I of this series. These theories would satisfy the "three classical tests" of general relativity, if the solar system were at rest in the "preferred frame." But instead it probably moves with a speed of ~200 km s-1. We use the new version of the Parametrized Post-Newtonian (PPN) formalism discussed in Paper I, to show that such motion may produce (1) an anomalous 12-hour sidereal tide of the solid Earth; (2) an anomalous yearly variation in the Earth's rotation rate; (3) an anomalous perihelion shift of the planets. We use gravimeter data, length-of-day data, and perihelion-shift data to put upper limits on the sizes of such anomalous effects. These limits rule out all the "preferred-frame" theories whose authors are listed above, and put an upper limit on the strength of a cosmological vector gravitational field. Other possible experimental tests of "preferred-frame" theories are discussed.