We present the first direct measurement of the gravity-field curvature based on three conjugated atom interferometers. Three atomic clouds launched in the vertical direction are simultaneously interrogated by the same atom interferometry sequence and used to probe the gravity field at three equally spaced positions. The vertical component of the gravity-field curvature generated by nearby sourc...

We show how classical spacetime emerges from quantum gravity through the study of a quantum FRW cosmological model coupled to a free massive scalar field using a new asymptotic expansion method of the Wheeler-DeWitt equation. It is shown that the coherent states of the nonadiabatic basis of a particular generalized invariant give rise to the quantum back reaction of matter field proportional to...

Drought indicators based on model-assimilated Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage observations" (2012). NASA Publications. [1] The Gravity Recovery and Climate Experiment (GRACE) twin satellites observe time variations in Earth's gravity field which yield valuable information about changes in terrestrial water storage (TWS). GRACE is characterized by low sp...

In contrast to gravity in the weak-field regime, which has been subject to numerous experimental tests, gravity in the strong-field regime is largely unconstrained by observations. We show that gravity theories that pass solar system tests, but that diverge from general relativity in the strong-field regime, predict neutron stars with significantly different properties than their general relati...

In both Newtonian gravity and Einstein there is no force on a test particle located inside spherical cavity cut out of static, spherically symmetric mass distribution. Inside the exterior matter decoupled external field effect that could act particle. However, for potentials other than potential or geometries Ricci flat ones this longer case, then an effect. We explore possibility in various al...

Unexpected energy increases during Earth flybys of both the Galileo and Near Earth Asteroid Rendezvous (NEAR) spacecraft have drawn evidence of spacecraft trajectory modeling errors, an unknown perturbing force or failure of Newtonian gravity. This paper will investigate the gravity field of Earth as a possible source of these anomalous AVs. Other possible sources of errors have been considered...

Mascon modeling is used in this paper to produce the mass flux solutions in the Tibetan Plateau. In the mascon modeling, the pseudo observations and their covariance matrices are derived from the GRACE monthly gravity field models. The sampling density of the pseudo observations is determined based on the eigenvalues of the covariance matrices. In the Tibetan Plateau, the sampling density of pe...

BACKGROUND Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T) inh...

This article provides a survey on modern methods of regional gravity field modeling on the sphere. Starting with the classical theory of spherical harmonics,weoutline the transition towards space-localizing methods such as spherical splines and wavelets. Special emphasis is given to the relations among these methods, which all involve radial base functions. Moreover, we provide extensive applic...