We study a general Scalar-Tensor Theory with an arbitrary coupling funtion !( ) but also an arbitrary dependence of the gravitational constant G( ) in the cases in which either one of them, or both, do not admit an analytical inverse, as in the hyperextended in ationary scenario. We present the full set of eld equations and study their cosmological behavior. We show that different scalar-tensor...

We present an introduction to ideas related to the holographic principle in the context of the well-established duality between classical gravity and conformal fluid dynamics. Foundations of relativistic hydrodynamics, conformal invariance, and geometry of anti-de Sitter spaces are discussed. We then detail an explicit calculation relating the dynamics of a non-stationary nonsymmetrical 3+1 dim...

Background: Accumulation of pleural and peritoneal fluid is seen in some diseases. In order to diagnose the disease and start the treatment, one of the most important actions will be to differentiate between exudates and transudates. The objective of this study was to determine the diagnostic value of measuring the specific gravity of the fluid through...

in this paper, it has been shown that there is a special relation between horizontal and vertical gradients of gravity data and the vertical and horizontal components of magnetic data for some of 2-d sources. it has been shown that the hilbert transform is useful in calculating the vertical gradient of gravity and magnetic anomalies from the horizontal gradient for transformation of gravity and...

We derive the effective four-dimensional gravity action in the RandallSundrum scenario in which two 3-branes of opposite tension reside in a fivedimensional spacetime. The dimensional reduction with the Ansatz for the radion field by Charmousis et al., which solves five-dimensional linearized field equations, results in a class of scalar-tensor gravity theories. In the limit of vanishing radion...

A bstract We study inflationary solution in an extension of mimetic gravity with the higher derivative interactions coupled to gravity. Because setup is free from ghost and gradient instabilities while it hosts a number novel properties. The dispersion relation scalar perturbations develop quartic momentum correction similar inflation. Furthermore, tilt tensor can take either signs modified con...

We discuss lowering the order of the two-dimensional scalar-tensor R2 quantum gravity, by mapping the most general version of the model to a multi-dilaton gravity, which is essentially the sigma-model coupled with the Jackiw-Teitelboim-like gravity. In the continuation of our previous research, we calculate the divergent part of the one-loop effective action in a 2D scalar-tensor (dilatonic) gr...

Introduction: Surface gravity surveying is a well developed terrestrial geophysical technique, used to detect subsurface density variations, which in turn can reveal subsurface geologic features. Here we perform a feasibility study to determine what major science questions can be answered by a rover-mounted, highly compact gravimeter and gravity gradiometer being designed by Gedex Inc.; a Toron...

Abstract—Gravity field is of great significance in geoscience, national economy and national security, and gravitational gradient measurement has been extensively studied due to its higher accuracy than gravity measurement. Gravity gradient sensor, being one of core devices of the gravity gradient instrument, plays a key role in measuring accuracy. Therefore, this paper starts from analyzing th...