No Arabic abstract
In the present work the rotation of polarization vector due to the gravitational field of a rotating body has been derived, from the general expression of Maxwells equation in the curved space-time. Considering the far field approximation (i.e impact parameter is greater than the Schwarzschild radius and rotation parameter), the amount of rotation of polarization vector as a function of impact parameter has been obtained for a rotating body (considering Kerr geometry). Present work shows that, the rotation of polarization vector can not be observed in case of Schwarzschild geometry. This work also calculates the effect, considering prograde and retrograde orbit for the light ray. Although the present work demonstrates the effect of rotation of polarization vector for electromagnetic wave (light ray), but it confirms that there would be no net polarization of electromagnetic wave due to the curved space-time geometry.
We perform an analysis where Einsteins field equation is derived by means of very simple thermodynamical arguments. Our derivation is based on a consideration of the properties of a very small, spacelike two-plane in a uniformly accelerating motion.
We aim to build a simple model of a gas with temperature ($T$) in thermal equilibrium with a black-body that plays the role of the adiabatically expanding universe, so that each particle of such a gas mimics a kind of particle (quantum) of dark energy, which is inside a very small area of space so-called Planck area ($l_p^{2}$), that is the minimum area of the whole space-time represented by a huge spherical surface with area $4pi r_u^2$, $r_u$ being the Hubble radius. So we should realize that such spherical surface is the surface of the black-body for representing the universe, whose temperature ($T$) is related to an acceleration ($a$) of a proof particle that experiences the own black-body radiation according to the Unruh effect. Thus, by using this model, we derive the law of universal gravitation, which leads us to understand the anti-gravity in the cosmological scenario and also estimate the tiny order of magnitude of the cosmological constant in agreement with the observational data.
It is shown that the internal solution of the Schwarzschild type in the Relativistic Theory of Gravitation does not lead to an {infinite pressure} inside a body as it holds in the General Theory of Relativity. This happens due to the graviton rest mass, because of the stopping of the time slowing down.
K0-K0bar oscillations are extremely sensitive to the K0 and K0bar energy at rest. Even assuming m_K0=m_K0bar, the energy is not granted to be the same if gravitational effects on K0 and K0bar slightly differ. We consider various gravitation fields present and, in particular, galactic fields, which provide a negligible acceleration, but relatively large gravitational potential energy. A constraint from a possible effect of this potential energy on the kaon oscillations isfound to be |(m_g/m_i)_K0-(m_g/m_i)_K0bar| < 8 x 10^-13 atCL=90%. The derived constraint is competitive with other tests of universality of the free fall. Other applications are also discussed.
Newtons Law of Gravitation has been tested at small values of the acceleration, down to a=10^{-10} m/s^2, the approximate value of MONDs constant a_0. No deviations were found.