THE EQUIVALENCE PRINCIPLE IN KALUZA–KLEIN GRAVITY

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...

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.

Equivalence Principle Implications of Modified Gravity Models

The Special Relativistic Equivalence Principle: Gravity Theory’s Foundation

Einstein’s Equivalence Principle asserts that physical phenomena occuring in a laboratory which undergoes constant acceleration through gravity-free inertial space should be identical in all respects to that which occurs in local gravity. By incorporating special relativity theory into an extended version of the Equivalence Principle — the Special Relativistic Equivalence Principle (SREP) — pos...

Universal Decoherence under Gravity: A Perspective through the Equivalence Principle.

Pikovski et al. [Nat. Phys. 11, 668 (2015)] show that a composite particle prepared in a pure initial quantum state and propagated in a uniform gravitational field undergoes a decoherence process at a rate determined by the gravitational acceleration. By assuming Einstein's equivalence principle to be valid, we analyze a physical realization of the (1+1)D thought experiment of Pikovski et al. t...