Spin-Gravity Interactions and Equivalence Principle

Gravity, Equivalence Principle and Clocks

String theory suggests the existence of gravitational-strength scalar fields (“dilaton” and “moduli”) whose couplings to matter violate the equivalence principle. This provides a new motivation for highprecision clock experiments, as well as a generic theoretical framework for analyzing their significance.

Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity

For a long time, it is generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism i...

Spin Structure of Nucleon and Equivalence Principle

The partition of nucleon spin between total angular momenta of quarks and gluons is described by the energy momentum tensor formfactors manifested also in the nucleon scattering by weak classical gravitational field. Natural generalization of equivalence principle is resulting in the identically zero ”Anomalous gravitomagnetic moment” being the straightforward analog of its electromagnetic coun...

Equivalence Principle Implications of Modified Gravity Models

The equivalence principle in Kaluza-Klein gravity

In four-dimensional general relativity the spacetime outside of an isolated spherical star is described by an unique line element, which is the Schwarzschild metric. However, theories that envision our world as embedded in a larger universe, with more than four dimensions, lead to a number of possible non-Schwarzschild exteriors. In five-dimensional Kaluza-Klein gravity the condition that in th...