RT Journal Article
SR Electronic
T1 Quantum theory and the equivalence principle
JF Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences
JO Proc R Soc Lond A Math Phys Sci
FD The Royal Society
SP 469
OP 478
DO 10.1098/rspa.1982.0084
VO 381
IS 1781
A1
A1
YR 1982
UL http://rspa.royalsocietypublishing.org/content/381/1781/469.abstract
AB The status of the gravitational principle of equivalence is obscure on the atomic scale, where quantum processes are relevant. On the assumption that a fundamental principle ought to apply to fundamental particles, we examine the principle of equivalence in a quantum context. We treat linearized gravitational perturbations as a massless, spin-two, gauge field coupled to itself and to matter, and argue that a consistent theory of this type, based on an action principle, is impossible unless the gravitational coupling is universal. The argument derives from a set of consistency conditions connecting successive orders of the perturbation expansion. We illustrate this consistency argument for scalar electrodynamics, and prove that the scalar particles must couple to gravity with the same strength as photons.