Gravitational redshift, equivalence principle, and matter waves

Equivalence principle and gravitational redshift.

We investigate leading order deviations from general relativity that violate the Einstein equivalence principle in the gravitational standard model extension. We show that redshift experiments based on matter waves and clock comparisons are equivalent to one another. Consideration of torsion balance tests, along with matter-wave, microwave, optical, and Mössbauer clock tests, yields comprehensi...

Dark-Matter-Induced Weak Equivalence Principle Violation

Quantum gravitational decoherence of matter waves

One of the biggest unsolved problems in physics is the unification of quantum mechanics and general relativity. The lack of experimental guidance has made the issue extremely evasive, though various attempts have been made to relate the loss of matter wave coherence to quantum spacetime fluctuations. We present a new approach to the gravitational decoherence near the Planck scale, made possible...

Gravitational waves from an early matter era

We investigate the generation of gravitational waves due to the gravitational instability of primordial density perturbations in an early matter-dominated era which could be detectable by experiments such as LIGO and LISA. We use relativistic perturbation theory to give analytic estimates of the tensor perturbations generated at second order by linear density perturbations. We find that large e...

The strong equivalence principle from a gravitational gauge structure

Gravitational self-interactions are assumed to be determined by the covariant derivative acting on the Riemann-Christoffel field strength. Once imposed on a metric theory, this Yang-Mills gauge constraint extends the equality of gravitational mass and inertial mass to compact bodies with non-negligible gravitational binding energy. Applied to generalized Brans-Dicke theories, it singles out one...