Relativistic jets are ubiquitous in astrophysical systems that contain central cores. They transport large amounts of energy to large distances from the source and their interaction with the ambient medium has a crucial effect on the evolution of the system. Furthermore, the radio luminosity exhibited by these jets are merely an indirect measure of the energy transported through the jets from the central engine which is not easily interpretable. The mechanism(s) responsible for these jet phenomena is still a subject of debate. In this work, we use both statistical and analytical methods to obtain a mathematical relation that may explain the observed physical processes in the evolution of astrophysical jets. We first obtain measured observable parameters characterizing these jets, and then carry out linear regressions of these parameters against each other to obtain a statistical relation. We also use analytical method to obtain a relation which in conjunction with the statistical relation yields a new relation that may explain how these jets interact with the ambient medium through which they propagate. Result shows that radio jet velocity () depends on the radio source energy density (u) and ambient particle number density () according to the relation, . This relation suggestively indicates that jet velocity has a direct power-law relationship with the source energy density and an inverse power-law relationship with the ambient particle number density.

There were two kinds of measurements of gravity deflection of light in general relativity. One was to measure the visible light’s deflection of stars during solar eclipses, and another was to measure the radio wave deflection of quasars. This paper revealed that these measurements had not verified the deflection value 1.75”predicted by general relativity actually. The reasons are as below. 1. All these measurements had not actually took into account the effects of the refraction index of atmospheric matter and the corona of the solar surface on the deflected light. 2. The measurements of visible light’s deflection were inaccurate and the obtained data had very large dispersion 3. The deviation caused by the fluctuation and refraction of the atmosphere on the earth's surface is not considered enough 4. The complex statistical methods such as the least square method and various parameters fitting were used to make the measured data consistent with the predictions of Einstein's theory, instead of directly observing the prediction values of Einstein's theory. 5. For the interference measurements of radio waves, the relative observation methods were used rather than the direct observation method, and interpretation of measurement results depended on theoretical models. In fact, astronomers tend to assume in advance that Einstein's theory was true, then by introducing a series of parameters to fit the measurements, so that the measurements always meet the Einstein's predictions. According to this method, a set of parameters can also be found to fit the measurement data so that the deflection of light can also satisfy the prediction of Newtonian gravity. The results are not unique. The conclusion of this paper is that the measurements of light’s gravity deflection of general relativity were invalid. In fact, according to the authors' published paper, general relativity did not predict that light in the solar gravitational field would be deflated by twice as much as the prediction of the Newton's theory of gravity. How could the observations detect such deflection?

The fundamental physical concept of shear stress, which governs fluid dynamics, is applied to the classical gravitational results of Newton and of Einstein, and leads naturally to an understanding of the origin of light in the Universe, through the existence of black holes. In this paper, we show how this occurs through an adjunct force of gravity normal to the Newtonian force of gravity, in which the turbulent fluctuations in velocity attain the velocity of light in a ring surrounding the black hole. The existence of this turbulent shear stress has previously been neglected.

Aims/ Objectives: Using the standard momentum-energy relation in special theory of relativity, we try to show that massless moving particle with velocity of light can contribute energy and momentum to the system of objects.

Study Design: Relativistic mass energy relation.

Place and Duration of Study: Retired Professor of Mathematics, Megna Apartment , Krishnapur, between June 2020 and July 2021.

Methodology: We have considered here the mass of a system of non-interacting particles and computation of M_{systerm} is in terms of unit mass m. Moreover we have considered here photon having no mass. But the presence of more than one of photon contribute energy because of increment of its mass in the system. And those photons considered here are non-interacting. The M_{systerm} of photon is also expressed in unit mass m.

Over the last few years, many of the available data from modern experimental techniques and sophisticated theoretical methods have become even more important to stellar spectroscopy. Obviously, the shape of the spectral line is conditioned by natural broadening, Doppler and collision broadening. In this paper, we have considered the Stark broadening as a dominant form of collision broadening of the spectral lines of singly ionized rhodium. Here, Stark broadening parameters widths and shifts have been calculated for 31 Rh II transitions using the simplified modified semiempirical method of Dimitrijevi´c and Konjevi´c. We analyzed our results for Stark shifts and compared these obtained values for the whole set of calculated transitions. Also, Stark widths were analyzed on an appropriate model of the atmosphere of chemically peculiar stars, type A.