Thermodynamic Properties of Yukawa-Schwarzschild Black Hole in Non-commutative Gauge Gravity

In this paper we construct a non-commutative gauge theory for the deformed metric corresponding to the modified structure of a gravitational field in the case of Yukawa-Schwarzschild non-commutative space-time. The thermodynamic properties and corrections to the gravitational force on the horizon of a non-commutative Yukawa-Schwarzschild black hole are analysed.Comment: 12 pages, 4 figure

Relativistic Spectrum of Hydrogen Atom in Space-Time Non-Commutativity

We study space-time non-commutativity applied to the hydrogen atom via the Seiberg-Witten map and its phenomenological effects. We find that it modifies the Coulomb potential in the Hamiltonian and add an r-3 part. By calculating the energies from Dirac equation using perturbation theory, we study the modifications to the hydrogen spectrum. We find that it removes the degeneracy with respect to the total angular momentum quantum number and acts like a Lamb shift. Comparing the results with experimental values from spectroscopy, we get a new bound for the space-time non-commutative parameter. N.B: In precedent works (arXiv:0907.1904, arXiv:1003.5732 and arXiv:1006.4590), we have used the Bopp Shift formulation of non-commutativity but here use it \`a la Seiberg-Witten in the Relativistic case.Comment: 5 pages, 1 table, ICPTP 2011 Constantine, Algeri

New treatment of the noncommutative Dirac equation with a Coulomb potential

Using the approach the modified Euler-Lagrange field equation together with the corresponding Seiberg-Witten maps of the dynamical fields, a noncommutative Dirac equation with a Coulomb potential is derived. We then find the noncommutative modification the energy levels and the possible new transitions. In the nonrelativistic limit a general form of the hamiltonian of the hydrogen atom is obtained, and we show that the noncommmutativity plays the role of spin and magnetic field which gives the hyper fine structure.Comment: 13 page

Particle creation in cosmological space-time by a time-dependent electric field

In this work, we calculate the particle creation density in a cosmological anisotropic Bianchi I universe, by solving the Klein-Gordon and Dirac equations in the presence of a time-dependent electric field using the semi-classical method. We show that the particles distribution becomes thermal under the influence of the electric field when the electric interaction proportional to the Ricci scalar of curved space-timeComment: 18 pages, 4 figure