Maia, Márcio Roberto GarciaCâmara Neto, Calistrato Soares da2014-12-172007-08-082014-12-172001-11-07CÂMARA NETO, Calistrato Soares da. Soluções cosmológicas e locais para uma eletrodinâmica modificada. 2001. 90 f. Dissertação (Mestrado em Física da Matéria Condensada; Astrofísica e Cosmologia; Física da Ionosfera) - Universidade Federal do Rio Grande do Norte, Natal, 2001.https://repositorio.ufrn.br/jspui/handle/123456789/16626The present work investigates some consequences that arise from the use of a modifed lagrangean for the eletromagnetic feld in two diferent contexts: a spatially homogeneous and isotropic universe whose dynamics is driven by a magnetic feld plus a cosmological parameter A, and the problem of a static and charged point mass (charged black hole). In the cosmological case, three diferent general solutions were derived. The first, with a null cosmological parameter A, generalizes a particular solution obtained by Novello et al [gr-qc/9806076]. The second one admits a constant A and the third one allows A to be a time-dependent parameter that sustains a constant magnetic feld. The first two solutions are non-singular and exhibit in ationary periods. The third case studied shows an in ationary dynamics except for a short period of time. As for the problem of a charged point mass, the solutions of the Einstein-Maxwell equations are obtained and compared with the standard Reissner-Nordstrom solution. Contrary to what happens in the cosmological case, the physical singularity is not removedapplication/pdfAcesso AbertoEletrodinâmicaSoluções cosmológicasModelos de Friedmann-Robertson-WalkerModelos de Reisner-NordströmElectrodynamicsCosmological solutionsStandard Friedmann-Robertson-WalkerStandard Reissner-NordströmEletrodinâmicaSoluções cosmológicasModelos de Friedmann-Robertson-WalkerElectrodynamicsCosmological solustionsStandard Friedmann-Robertson-WalkerStandard Reissner-NordströmmasterThesisCNPQ::CIENCIAS EXATAS E DA TERRA::FISICA