Model-dependence of Shapiro time delay and the speed of gravity/speed of light controversy

2004/03/31 by S. Carlip, Steven Carlip · 55 citations
Physics and Astronomy · #Class (philosophy) #Classical mechanics #Computer science #Context (archaeology) #Cosmology and Gravitation Theories #Epistemology #Field (mathematics) #General relativity #Gravitation #Gravitational field #Gravitational redshift #Measure (data warehouse) #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #Relativity and Gravitational Theory #Speed of gravity #Speed of light (cellular automaton) #Theoretical physics #astro-ph #gr-qc

paper · pdf · doi:10.1088/0264-9381/21/15/011

published in Classical and Quantum Gravity 21(15), 3803-3812 (IOP Publishing) · 12 pages, LaTeX; v2: added discussion of present observational limits, and of relative importance of various contributions to time delay; new references; v3: minor clarifications in response to referee

arxiv created 2004/06/02 · openalex publication_date 2004/07/21 · arxiv updated 2010/04/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Fomalont and Kopeikin have recently succeeded in measuring the velocity-dependent component of the Shapiro time delay of light from a quasar passing behind Jupiter. While there is general agreement that this observation tests the Lorentz transformation properties of the gravitational field, a controversy has emerged over the question of whether the results depend on the speed of light, c, or the speed of gravity, c_g. By analyzing the Shapiro time delay in a set of "preferred frame" models, I demonstrate that this question is ill-posed: the distinction can only be made in the context of a class of theories in which c\≠ c_g, and the answer then depends delicately on the specific class of theories one chooses.

Citations

• Lower bound on the propagation speed of gravity from gravitational Cherenkov radiation
• The post-Newtonian treatment of the VLBI experiment on September 8, 2002
• Propagation Speed of Gravity and the Relativistic Time Delay
• The speed of gravity in general relativity and theoretical interpretation of the Jovian deflection experiment
• A test of general relativity using radio links with the Cassini spacecraft
• Gravity with a dynamical preferred frame

Cited by

• Radio interferometric tests of general relativity
• Emergence of a universal limiting speed
• Covariant equations of motion beyond the spin-dipole particle approximation
• Rømer time-delay determination of the gravitational-wave propagation speed