Equivalence principle implications of modified gravity models

Equivalence Principle Implications of Modified Gravity Models

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.

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...

Conformal Equivalence of 2d Dilaton Gravity Models

We investigate the behavior of generic, matter-coupled, 2D dilaton gravity theories under dilaton-dependent Weyl rescalings of the metric. We show that physical observables associated with 2D black holes, such as the mass, the temperature and the flux of Hawking radiation are invariant under the action of both Weyl transformations and dilaton reparametrizations. The field theoretical and geomet...

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...