Detection of subsurface structures by means of gravity method can be used to determine mass distribution and density contrast of rock units. This distribution could be detected by different geophysical methods, especially gravity method. However, gravity techniques have some drawbacks and can't be always successful in distinguishing subsurface structures. Performance of the gravity technique co...

We point out that extended gravity theories, the Lagrangian of which is an arbitrary function of scalar curvature R, are equivalent to a class of the scalar tensor theories of gravity. The corresponding gravity theory is ω = 0 BransDicke gravity with a potential for the Brans-Dicke scalar field, which is not compatible with solar system experiments if the field is very light: the case when such...

This study integrates development aid into a theoretically founded structural gravity model that considers primary and secondary effects of as an income transfer bilateral trade cost determinant. We identify the parameters our using two-stage approach includes state-of-the-art Poisson pseudo-maximum likelihood estimation for sample 132 countries over period 1995 to 2012. The main findings indic...

In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry can not be directly applied to gauge theory of gravity. In gauge theory of gravity, based on the viewpoint of the coupling between the spin and gravitational field, an equation of motion of the spin is deduc...

Atmospheric gravity waves play fundamental roles in a broad-range of dynamical processes extending throughout the Earth’s neutral atmosphere and ionosphere. In this paper, we present a modified form for the acoustic-gravity wave equation and its dispersion relationships for a compressible and non-stationary atmosphere in hydrostatic balance. Importantly, the solutions have been achieved without...

where Lm is the matter part Lagrangian. The gravitational field equation is presented in Eq. (2) of [1]. In contrast with the situation with generalized f(φ,R) gravity in Eq. (27), the gravity with Ricci-curvature square term in the action does not have the conformal symmetry to Einstein gravity [2]. In [1] we analysed the gravitational wave and derived a fourth order differential equation. How...

We discuss the large N limit of the supersymmetric CP N models as an illustration of Cecotti and Vafa's tt * formalism. In this limit the 'tt * equation' becomes the long wavelength limit of the 2D Toda lattice, an equation first studied in the context of self-dual gravity. We show how simple finite temperature and large N techniques determine the relevant solution, and verify analytically that...

A systematic method is developed to study classical motion of a mass point in gravitational gauge field. First, the formulation of gauge theory of gravity in arbitrary curvilinear coordinates is given. Then in spherical coordinates system, a spherical symmetric solution of the field equation of gravitational gauge field is obtained, which is just the Schwarzschild solution. In gauge theory of g...

Although initially originated as a totally empirical relationship to explain the volume of trade between two partners, gravity equation has been the focus of several theoretic models that try to explain it. Specialization models are of great importance in providing a solid theoretic ground for gravity equation in bilateral trade. Some research papers try to improve specialization models by addi...