Navegando por Autor "FIGUEIRA, Rodrigo Murta de Andrade"

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Acesso aberto (Open Access)
Electric charge rotating around a black hole
(2005-12) CASTIÑEIRAS RODRÍGUEZ, Jorge; CRISPINO, Luís Carlos Bassalo; FIGUEIRA, Rodrigo Murta de Andrade; MATSAS, George Emanuel Avraam
We consider an electric charge rotating around a Schwarzschild black hole. We compute, using quantum field theory in curved spacetime at the tree level, the power emitted by the rotating charge minimally coupled to the Maxwell field. We also compute how much of the radiation emitted by the swirling charge is absorbed by the black hole.
Acesso aberto (Open Access)
Radiação emitida por uma carga elétrica orbitando um buraco negro de Schwarzschild segundo Teoria Quântica de Campos
(Universidade Federal do Pará, 2004-01-21) FIGUEIRA, Rodrigo Murta de Andrade; CRISPINO, Luís Carlos Bassalo; http://lattes.cnpq.br/4033994493756291
We performthe quantization of the massless vector field in Minkowski and Schwarz-schild spacetimes, and calculate the radiated power by an electric charge in a circular orbit around an object with mass M in both spacetimes. In the Minkowski case wend the analytical expression for the radiated power using quantum field theory and assuming Newtonian gravity. It coincides with classical Larmors result, since the calculations are performed at the tree level. Since in the Schwarzschild case it is not possible to express the solution of the radial equation in terms of well known special functions, we adopt the following two approaches: analytical approximation in the low frequency limit and numerical computing. The first approach was used as a consistency check for the numerical one. We also use quantum eld theory at tree level in the Schwarzschid case, and the radiated power is obtained both in the low frequency limit as well as numerically. After comparing the results, we conclude that for the same angular velocity of the charge (as measured by asymptotical static observers), the radiated power in Minkowski spacetime is bigger than in Schwarzschild case.