List of Figures

View Image Figure 1:
Selected tests of the weak equivalence principle, showing bounds on j, which measures fractional difference in acceleration of different materials or bodies. The free-fall and Eöt-Wash experiments were originally performed to search for a fifth force (green region, representing many experiments). The blue band shows evolving bounds on j for gravitating bodies from lunar laser ranging (LLR).
View Image Figure 2:
Selected tests of local Lorentz invariance showing the bounds on the parameter d, which measures the degree of violation of Lorentz invariance in electromagnetism. The Michelson-Morley, Joos, Brillet-Hall and cavity experiments test the isotropy of the round-trip speed of light. The centrifuge, two-photon absorption (TPA) and JPL experiments test the isotropy of light speed using one-way propagation. The most precise experiments test isotropy of atomic energy levels. The limits assume a speed of Earth of 370 km s-1 relative to the mean rest frame of the universe.
View Image Figure 3:
Selected tests of local position invariance via gravitational redshift experiments, showing bounds on a, which measures degree of deviation of redshift from the formula Dn/n = DU/c2. In null redshift experiments, the bound is on the difference in a between different kinds of clocks.
View Image Figure 4:
Geometry of light deflection measurements.
View Image Figure 5:
Measurements of the coefficient (1 + g)/2 from light deflection and time delay measurements. Its GR value is unity. The arrows at the top denote anomalously large values from early eclipse expeditions. The Shapiro time-delay measurements using the Cassini spacecraft yielded an agreement with GR to 10- 3 percent, and VLBI light deflection measurements have reached 0.02 percent. Hipparcos denotes the optical astrometry satellite, which reached 0.1 percent.
View Image Figure 6:
Constraints on masses of the pulsar and its companion from data on B1913+16, assuming GR to be valid. The width of each strip in the plane reflects observational accuracy, shown as a percentage. An inset shows the three constraints on the full mass plane; the intersection region (a) has been magnified 400 times for the full figure.
View Image Figure 7:
Plot of the cumulative shift of the periastron time from 1975-2005. The points are data, the curve is the GR prediction. The gap during the middle 1990s was caused by a closure of Arecibo for upgrading [272].
View Image Figure 8:
The six polarization modes for gravitational waves permitted in any metric theory of gravity. Shown is the displacement that each mode induces on a ring of test particles. The wave propagates in the +z direction. There is no displacement out of the plane of the picture. In (a), (b), and (c), the wave propagates out of the plane; in (d), (e), and (f), the wave propagates in the plane. In GR, only (a) and (b) are present; in massless scalar-tensor gravity, (c) may also be present.