http://popups.lib.uliege.be/1373-5411/index.php?id=1263 Publications of Auteurs Alen Novakovic fr 0 http://popups.lib.uliege.be/1373-5411/index.php?id=2378 The proposed model of the universe motion gives some new specific answers to the important questions of the cosmology: what occurred at the initial singularity?, how old is the universe?, how big is the universe?, and what is it's ultimate fate? This new approach is based on the new solution of the Einstein's field equations in a vacuum. This solution confirms that the so called cosmological constant, ʌ, is not really constant, but a function of the gravitational radius. As the consequence, the acceleration equation of the universe motion shows that the universe acceleration can be attractive (negative) or repulsive (positive). The repulsive acceleration gives rise to the accelerating expansion of the universe at the present time. The change from the contracting phase into the expanding one, takes place at the minimal radius,r=GM/2c². This could be the solution of the initial singularity. Fri, 02 Aug 2024 11:51:44 +0200 Fri, 02 Aug 2024 11:51:51 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=2378 http://popups.lib.uliege.be/1373-5411/index.php?id=1726 Because a scalar potential of a gravitational field has a unit of a specific energy (J/kg), the problem of unification of potential fields has been transformed into the problem of unification of specific potential energies of a particle in a multi-potential field. Consequently, the parameter α and α' of GLT model become the functions of a unified specific potential energy in a multi-potential field. Since all items like field tensors and Klein, Gordon and Fock equation are functions of parameters α and α', these items can be applied to multi-potential fields. Thus, a field tensor of a unified specific potential energy of a particle in central symmetric electromagnetic and gravitational fields in vacuum is derived. Finally, it has been shown that a momentum equation of photons will remain unchanged even if the photons may have the mass. Tue, 16 Jul 2024 14:18:53 +0200 Tue, 16 Jul 2024 14:19:03 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=1726 http://popups.lib.uliege.be/1373-5411/index.php?id=1255 A new General Lorentz Transformation model (GLT-model) derived by Novakovic ( 1999) for the particle motion in x-axis only, has been extended to the full form including y and z - axes. Starting with this transformation model, a general line element and a corresponding general metric tensor of GLT - model have been derived. The general line element and the metric tensor are functions of two free parameters α and α' , which are the functions of the space-time coordinates. The identification of two free parameters of GLT-model has been done for a weak and a strong gravitational field. The weak gravitational field solution of the two free parameters of GLT-model corresponds to the well-known Schwartzschild's metrics of the line element, for a spherically symmetric non-rotating body. It is very important to point out that the line element of GLT-model given in a non-diagonal form has got a very important property: non-singularity in a very strong gravitational field. Finally, a simple coordinate transformation procedure has been derived that transforms a general line element into diagonal one, with metric components (-1, 1, 1, 1), equal to the metrics in Special Relativity. Since the all items in SR and GR can be described as the functions of two free parameters of GLT-model, the possibilities of an unification of Einstein's Special and General Theories of Relativity, as well as a new unification of electromagnetic and gravitational fields are opened. Wed, 10 Jul 2024 09:47:56 +0200 Mon, 07 Oct 2024 15:44:23 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=1255