Relativistic tidal forces.
Abstract
The postNewtonian, relativistic (1/csquared) tidal force is calculated within the general PPN framework of all metric theories of gravity. There are no relativistic tides in general relativity, but they are generally nonzero in other metric theories of gravity, including scalartensor theories. In close binaries, such as the binary pulsar system PSR 1913+16, the relativistic tides can be orders of magnitude larger than Newtonian tides. In 'preferred frame' theories of gravity in which the PPN coefficient alpha(1) is nonzero, the relativistic tidal field is not the gradient of a scalar potential, but includes also a circulating, nonconservative field in a body.
 Publication:

The Astrophysical Journal
 Pub Date:
 January 1983
 DOI:
 10.1086/160633
 Bibcode:
 1983ApJ...264..620N
 Keywords:

 Binary Stars;
 Free Fall;
 Gravitation Theory;
 Relativity;
 Tides;
 Equations Of Motion;
 Pulsars;
 Scalars;
 SpaceTime Functions;
 Astrophysics