Bezmasene čestice spina 1 u rotirajućem prostoru-vremenu

We consider the massless Duffin-Kemmer-Petiau equation for the general rotating space-times, then find its second-order form for a given geometry. Using this second-order differential equation for two well-known cosmological models, the exact solutions of the massless Duffin-Kemmer-Petiau equation were obtained. On the other hand, by using spinor form of the Maxwell equations, the propagation problem is reduced to the solution of the second-order differential equation of a complex combination of the electric and magnetic fields. For these two different approaches, we obtain the spinors in terms of the field-strength tensor.Razmatramo bezmasenu jednadžbu Duffin–Kemmer–Petiau-a za opći slučaj rotirajućeg prostora-vremena i nalazimo njen oblik drugog reda za pojedinu geometriju. Primjenom te jednadžbe drugog reda postigli smo egzaktna rješenja Duffin– Kemmer–Petiau-ve jednadžbe za dva poznata kozmološka modela. Pored toga, primjenom Maxwellovih jednadžbi u spinornom obliku, problem širenja valova svodi se na rješavanje diferencijalne jednadžbe drugog reda za kompleksni slog električnih i magnetskih polja. Tim dvama pristupima dobivamo spinore izražene preko tenzora jakosti polja

Creation of Spin-1/2 Particles in the Hyperboloid de Sitter Space-Time

In this work we solve Dirac equation by using the method of seperation of variables. Then we analyzed the particle creation process. To compute the density number of particles created Bogoliubov transformation technique is used.Comment: 5 pages, no figures, presented at the 1st Int. Hellenic&Turkish Phys. Con

Total Energy of Charged Black Holes in Einstein-Maxwell-Dilaton-Axion Theory

We focus on the energy content (including matter and fields) of the Møller energy-momentum complex in the framework of Einstein-Maxwell-Dilaton-Axion (EMDA) theory using teleparallel gravity. We perform the required calculations for some specific charged black hole models, and we find that total energy distributions associated with asymptotically flat black holes are proportional to the gravitational mass. On the other hand, we see that the energy of the asymptotically nonflat black holes diverge in a limiting case

Energy in Reboucas Tiomno Korotkii Obukhov and Godel type Space times in Bergmann Thomson s Formulations

We calculate the total energy (the matter plus fields) of the universe considering Bergmann- Thomson's energy-momentum formulation in both Einstein's theory of general relativity and tele-parallel gravity on two different space-times; namely Reboucas-Tiomno-Korotkii-Obukhov and the G¨odel-type metrics. We also compute some kinematical quantities for these space-times and nd that these space-times have shear-free expansion and non-vanishing four-acceleration and vorticity. Different approximations of the Bergmann-Thomson energy momentum formulation in these different gravitation theories give the same energy density and agree with each other. The results advocate the importance of energy-momentum definitions