New Solutions of Einstein Equations in Spherical Symmetry: The Cosmic Censor to the Court

Giambò, Roberto; Giannoni, Fabio; Magli, Giulio; Piccione, Paolo

doi:10.1007/s00220-003-0793-9

Cited by 65 publications

(77 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, the CCC remains unproved and there exists no mathematically precise and definite statement for the CCC which one could try to prove (see e.g. [1][2][3][4][5][6] for some recent reviews, and references therein).…”

mentioning

confidence: 99%

Timelike naked singularity

et al. 2004

View full text Add to dashboard Cite

We construct a class of spherically symmetric collapse models in which a naked singularity may develop as the end state of collapse. The matter distribution considered has negative radial and tangential pressures, but the weak energy condition is obeyed throughout. The singularity forms at the center of the collapsing cloud and continues to be visible for a finite time. The duration of visibility depends on the nature of energy distribution. Hence the causal structure of the resulting singularity depends on the nature of the mass function chosen for the cloud. We present a general model in which the naked singularity formed is timelike, neither pointlike nor null. Our work represents a step toward clarifying the necessary conditions for the validity of the Cosmic Censorship Conjecture. The cosmic censorship conjecture (CCC) has been widely recognized as one of the most important open problems in gravitational physics today. This is because several important areas in the theory and applications of black hole physics crucially depend on CCC. Nevertheless, the CCC remains unproved and there exists no mathematically precise and definite statement for the CCC which one could try to prove (see e.g. [1-6] for some recent reviews, and references therein).For this reason a detailed study of dynamically developing gravitational collapse models within the framework of general relativity becomes rather essential. The hope is that such a study may allow us to formulate a provable statement of the CCC, if it is correct in some form. Such investigations also help us to discard certain statements of the CCC which might sound plausible but for which there exist counter-examples which show that the CCC cannot be valid in such a form. They may even illustrate the physical conditions that give rise to naked singularities (NS) or black holes (BH) as end states of a realistic gravitational collapse. So far, such dynamical collapse studies have focused largely on collapse models that create either BH or NS, depending on the nature of the initial profiles of density, pressure, and velocity from which the collapse develops. In many of these cases, when a NS develops, it is located at the center of the spherically symmetric cloud (a central singularity, see e.g. [5][6][7]). In that case, there will exist families of non-spacelike future directed geodesics, which will be accessible to distant observers in the future, and which will terminate at the singularity in the past, thus making it visible in principle. This is opposed to the BH case where the apparent horizon forms early enough to cover all of the singularity, with no portion of it remaining visible to outside observers.If we require the pressure to be positive then the "central" singularity, if it is naked, corresponds to a singularity along a visible null line. The remainder of the singularity is spacelike and covered by a horizon. In this paper, however, we permit the pressure to be negative and examine the structure of the singularity. We construct an explicit solution in which...

show abstract

mentioning

confidence: 99%

Timelike naked singularity

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Subsequently, the area-radius framework has been successfully applied to models of gravitational collapse and cosmic censorship (see e.g. [13,18,30]). …”

Section: Reduction Of the Field Equations Tomentioning

confidence: 99%

“…[16,18,20,21]). Besides the details of the physics of the collapse of such systems, the general pattern arising from all such examples is that existence of naked singularities persists in presence of stresses: actually, we have recently shown that the mechanism responsible for the formation or whatsoever of a naked singularity is the same in all such cases [13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Naked Singularities Formation in the Gravitational Collapse of Barotropic Spherical Fluids

Giambò

Giannoni

Magli

et al. 2004

General Relativity and Gravitation

Self Cite

View full text Add to dashboard Cite

ABSTRACT. The gravitational collapse of spherical, barotropic perfect fluids is analyzed here. For the first time, the final state of these systems is studied without resorting to simplifying assumptions -such as self-similarity -using a new approach based on non-linear o.d.e. techniques, and formation of naked singularities is shown to occur for solutions such that the mass function is analytic in a neighborhood of the spacetime singularity.

show abstract

“…scalar fields [15][16][17][18], perfect fluids [19][20][21][22][23][24], imperfect fluids [25][26][27][28] and null strange quark fluids [29,30]. The analysis has also been taken to wider gravitational settings, such as f (R) theories [31], Lovelock gravity [32] (see also [33][34][35][36][37][38] for some recent reviews) and hypothesized quantum gravity theories . This is an interesting line of research because, the possible discovery of naked singularities may provide us with an opportunity to extract information from physics beyond trans-Planckian regimes [69]; see e.g.…”

Section: Introductionmentioning

confidence: 99%

Einstein–Cartan gravitational collapse of a homogeneous Weyssenhoff fluid

et al. 2014

View full text Add to dashboard Cite

We consider the gravitational collapse of a spherically symmetric homogeneous matter distribution consisting of a Weyssenhoff fluid in the presence of a negative cosmological constant. Our aim is to investigate the effects of torsion and spin averaged terms on the final outcome of the collapse. For a specific interior space-time setup, namely the homogeneous and isotropic FLRW metric, we obtain two classes of solutions to the field equations where depending on the relation between spin source parameters, (i) the collapse procedure culminates in a space-time singularity or (ii) it is replaced by a non-singular bounce. We show that, under certain conditions, for a specific subset of the former solutions, the formation of trapped surfaces is prevented and thus the resulted singularity could be naked. The curvature singularity that forms could be gravitationally strong in the sense of Tipler. Our numerical analysis for the latter solutions shows that the collapsing dynamical process experiences four phases, so that two of which occur at the pre-bounce and the other two at post-bounce regimes. We further observe that there can be found a minimum radius for the apparent horizon curve, such that the main outcome of which is that there exists an upper bound for the size of the collapsing body, below which no horizon forms throughout the whole scenario.

show abstract

New Solutions of Einstein Equations in Spherical Symmetry: The Cosmic Censor to the Court

Cited by 65 publications

References 18 publications

Timelike naked singularity

Timelike naked singularity

Naked Singularities Formation in the Gravitational Collapse of Barotropic Spherical Fluids

Einstein–Cartan gravitational collapse of a homogeneous Weyssenhoff fluid

Contact Info

Product

Resources

About