Here we constructed a charged gravastar model formed by an interior de Sitter spacetime, a charged dynamical infinitely thin shell with an equation of state and an exterior de Sitter-Reissner-Nordstrom spacetime. We f...Here we constructed a charged gravastar model formed by an interior de Sitter spacetime, a charged dynamical infinitely thin shell with an equation of state and an exterior de Sitter-Reissner-Nordstrom spacetime. We find that the presence of the charge is crucial to the stability of these structures. It can as much favor the stability of a bounded excursion gravastar, and still converting it in a stable gravastar, as make disappear a stable gravastar, depending on the range of the charge considered. There is also formation of black holes and, above certain values, the presence of the charge allows the formation of naked singularity. This is an important example in which a naked singularity emerges as a consequence of unstabilities of a gravastar model, which reinforces that gravastar is not an alternative model to black hole.展开更多
基金The financial assistance from FAPERJ/UERJ(CFCB and MFAdaS)is gratefully acknowledgedThe authors(RC,MFAdaS)acknowledge the financial support from FAPERJ(no.E-26/171.754/2000,E-26/171.533/2002,E-26/170.951/2006,E-26/110.432/2009 and E-26/111.714/2010)+1 种基金The authors(RC and MFAdaS)also acknowledge the financial support from Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq-Brazil(no.450572/2009-9,301973/2009-1 and 477268/2010-2)The author(MFAdaS)also acknowledges the financial support from Financiadora de Estudos e Projetos-FINEP-Brazil(Ref.2399/03).
文摘Here we constructed a charged gravastar model formed by an interior de Sitter spacetime, a charged dynamical infinitely thin shell with an equation of state and an exterior de Sitter-Reissner-Nordstrom spacetime. We find that the presence of the charge is crucial to the stability of these structures. It can as much favor the stability of a bounded excursion gravastar, and still converting it in a stable gravastar, as make disappear a stable gravastar, depending on the range of the charge considered. There is also formation of black holes and, above certain values, the presence of the charge allows the formation of naked singularity. This is an important example in which a naked singularity emerges as a consequence of unstabilities of a gravastar model, which reinforces that gravastar is not an alternative model to black hole.