Improved Bounds on Violation of the Strong Equivalence Principle
  I describe a unique, 20-year-long timing program for the binary pulsar B0655+64, the stalwart control experiment for measurements of gravitational radiation damping in relativistic neutron-star binaries. Observed limits on evolution of the B0655+64 orbit provide new bounds on the existence of dipolar gravitational radiation, and hence on violation of the Strong Equivalence Principle. 
Z. Arzoumanian (USRA/NASA-GSFC)