TensorScalar Gravity and BinaryPulsar Experiments
Abstract
Some recently discovered nonperturbative strongfield effects in tensorscalar theories of gravitation are interpreted as a scalar analog of ferromagnetism: 'spontaneous scalarization'. This phenomenon leads to very significant deviations from general relativity in conditions involving strong gravitational fields, notably binarypulsar experiments. Contrary to solarsystem experiments, these deviations do not necessarily vanish when the weakfield scalar coupling tends to zero. We compute the scalar 'form factors' measuring these deviations, and notably a parameter entering the pulsar timing observable gamma through scalarfieldinduced variations of the inertia moment of the pulsar. An exploratory investigation of the confrontation between tensorscalar theories and binarypulsar experiments shows that nonperturbative scalar field effects are already very tightly constrained by published data on three binarypulsar systems.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 March 1996
 Bibcode:
 1996STIN...9816896D
 Keywords:

 Gravitation;
 Neutron Stars;
 Gravitational Fields;
 Pulsars;
 Binary Stars;
 Tensors;
 Scalers;
 Inequalities;
 Ferromagnetism;
 Form Factors;
 Solar System;
 Scalars;
 Relativity;
 Observation;
 Moments Of Inertia;
 Astrophysics