Soluções cosmológicas e locais para uma eletrodinâmica modificada

• Autor(a) principal: Câmara Neto, Calistrato Soares da
• Data de Publicação: 2001
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/16626
• topic: Eletrodinâmica; Soluções cosmológicas; Modelos de Friedmann-Robertson-Walker; Modelos de Reisner-Nordström; Eletrodinâmica; Soluções cosmológicas; Modelos de Friedmann-Robertson-Walker; Electrodynamics; Cosmological solutions; Standard Friedmann-Robertson-Walker; Standard Reissner-Nordström; Electrodynamics; Cosmological solustions; Standard Friedmann-Robertson-Walker; Standard Reissner-Nordström; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

The 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 removed