Dynamics Of Compact Objects Research Articles

Axially and reflection symmetric systems and structure scalars in [formula omitted] gravity

This manuscript is devoted to a general study on axial and reflection-symmetric self-gravitating sources in the background of f(R,T) gravity, where T represents the trace of stress energy-tensor, while R is the Ricci scalar. For this purpose, all the fundamental equations and notions set to carry out the general study are established. The corresponding field, as well as dynamical equations, are also exhibited. In order to discuss the thermodynamics aspects of the selected system, the modified transport equation is presented. The Weyl-tensor is utilized to evaluate the generalized version of scalar variables termed structure scalars. To produce modified scalar equations, we employ the structure scalars. The applications of our obtained results are examined on the dynamics of the source in f(R,T) gravity. We conclude that the modified structure scalars play an important role in the dynamics of compact objects.

Dynamics of non-adiabatic gravitating compact object in f(R, T) gravity

In this paper, we have discussed the dynamics of non-adiabatic gravitating compact object in f(R, T) theory using the Misner–Sharp approach. Here, we have extended the work of Herrera and Santos, to the modified f(R, T) theory of gravity. In order to discuss the effects of heat flux on the dynamics of compact object, we have taken the non-adiabatic source inside spherically symmetric compact object and modified field equations have been evaluated in f(R, T) gravity. The Misner–Sharp mass has been used to discuss the variation of total energy inside the gravitating compact object. The dynamical equations have been formulated by using the Bianchi identities in f(R, T) gravity. Further, the dynamical equations have been coupled with the heat transportation equation resulting from the framework of Mu¨ller–Israel–Stewart formalism. To analyze the results deeper, we have used the functional form of f(R, T) model, for such model the matter-curvature coupling constant λ has some direct effects on inertial mass density and gravitational forces. It makes the gravitational force less active thereby reducing the rate of collapse.

Radioastron: Main results of the implementation of the early science program in studies of astronomical objects in the universe with ultra-high angular resolution

The paper presents the main results of the implementation of the Radioastron Early Science Program. Interferometric responses (fringes) were obtained for all types of studied radio sources (quasars, pulsars and cosmic masers) and in all ranges of wavelengths (from meter to centimeter range) with large spaceground baselines. Such measurements have provided a record angular resolution, in some cases reaching several tens of microseconds of arc. This brings unique scientific results concerning the nature of the processes occurring in the vicinity of the supermassive black holes, the structure of the interstellar plasma inhomogeneities and dynamics of compact objects in star-forming regions.