Related papers: On the response of gravitational antennas to dilat…
The detection of gravitational waves based on the geodesic deviation equation is discussed. In particular, it is shown that the only non-vanishing components of the wave field in the conventional traceless-transverse gauge in linearized…
We analyze the response of the gravitational wave detector to a scalar massive plane gravitational wave. We give the compact form of the response and discuss its angular and frequency characteristics. The derivations is carried out in the…
The response of a gravitational wave detector to scalar waves is analysed in the framework of the debate on the choice of conformal frames for scalar-tensor theories. A correction to the geodesic equation arising in the Einstein conformal…
The variational field equations of Brans-Dicke scalar-tensor theory of gravitation are given in a non-Riemannian setting in the language of exterior differential forms over 4-dimensional spacetime. The class of pp-wave metrics together with…
We consider the cosmological amplification of a metric perturbation propagating in a higher-dimensional Brans-Dicke background, including a non trivial dilaton evolution. We discuss the properties of the spectral energy density of the…
We present a new approach to the theory of static deformations of elastic test bodies in general relativity based on a generalization of the concept of frame of reference which we identify with the concept of quo-harmonic congruence. We…
We propose a new method of searching for the composition-dependent dilatonic waves, predicted by unified theories of strings. In this method, Earth's surface-gravity changes due to translational motions of its inner core, excited by…
A specific choice of gauge is shown to imply a decoupling between the tensor and scalar components of Gravitational Radiation in the context of Brans-Dicke type theories of gravitation. The comparison of the predictions of these theories…
We argue that the dielectric effect, mostly studied for systems of coincident D-branes, is also extendible to configurations of multiple gravitational waves. We provide some evidence that Matrix string theory has an alternative…
An exact, plane wave solution of the gravitational field equations is investigated. The source stress tensor is represented by an anisotropic null fluid with energy flux to which the energy density $\rho$ and all pressures are finite…
Models of string cosmology predict a stochastic background of gravitational waves with a spectrum that is strongly tilted towards high frequencies. I give simple approximate expressions for spectral densities of the cosmic background which…
In the context of the bosonic string theory, we shall extract the general radiation amplitude of a massless closed string from the interaction of two parallel unstable D$p$-branes. The branes are non-stationary and have been dressed by…
There is an extremely simple relationship between the spectrum of the gravitational wave background produced by a cosmological distribution of discrete gravitational wave sources, the total time-integrated energy spectrum of an individual…
Gravitational waves offer a potent mean to test the underlying theory of gravity. In general theories of gravity, such as scalar-tensor theories, one expects modifications in the friction term and the sound speed in the gravitational wave…
A valuable target for advanced gravitational-wave detectors is the stochastic gravitational-wave background. The stochastic background imparts a weak correlated signal into networks of gravitational-wave detectors, and so standard searches…
General relativity considers Dixon's theory as the standard theory to deal with the motion of extended bodies in a given gravitational background. We discuss here the features of the "reaction" of an extended body to the passage of a weak…
Using the renormalization-group formalism, a sigma model of a special type- in which the metric and the dilaton depend explicitly on one of the string coordinates only-is investigated near two dimensions. It is seen that dilatonic gravity…
The gravitational wave solutions obtained from a perturbation about conformally flat backgrounds in Einstein gravity are investigated. A perturbation theory analysis of the Lesame, Ellis and Dunsby results, based on a covariant approach,…
In a modified gravity theory, the propagation equation of gravitational waves will be presented in a non-standard way. Therefore this tenor mode perturbation of time-space, as a complement to the scalar mode perturbation, provides a unique…
The gravitational fields of vacuumless global and gauge strings have been studied in Brans-Dicke theory under the weak field assumption of the field equations. It has been shown that both global and gauge string can have repulsive as well…