Naked singularity explosion in higher-dimensional dust collapse

Abstract

Abstract.In the context of the large extra dimensions or TeV-scale gravity, it has been argued that an effective naked singularity, called the visible border of spacetime, would be generated by high-energy particle collisions. Motivated by this interesting possibility, we investigate a particle creation by a naked singularity in general dimensions, adopting a spherically symmetric self-similar dust collapse as the simple model of a naked singularity formation. The power and energy of the particle emission behave in two distinct ways depending on a parameter in the model. In a generic case, the emission power is proportional to the quadratic inverse of the remaining time to the Cauchy horizon, which has been known for the four-dimensional case in the literature. On the other hand, in a degenerate case the emission power is proportional to the quartic inverse of the remaining time to the Cauchy horizon, and depends on the total mass of a dust fluid in spite that the central region of the collapse is scale-free due to the self-similarity. In the both cases, within a test-field approximation the energy radiated before any quantum gravitational effect dominates amounts to TeV. This suggests that a backreaction is not ignorable in the TeV-scale gravity context, in contrast to the similar phenomena in stellar collapse.

Gravitational Collapse and Singularity Removal in Rastall Theory

“…where ρ i = ρðt i Þ and a i = aðt i Þ are the initial values of energy density and scale factor, respectively, and t = t i is the initial time at which the collapse begins. Equations (12) and (13) can then be rewritten as (we set the units so that…”

“…However, during the past decades, many examples of naked singularity formation as possible counterexamples to the cosmic censorship conjecture have been reported in the literature, among which we can quote gravitational collapse of dust, perfect fluids, and radiation shells [8,9]. Such a study has been extended to gravitational collapse in the presence of a cosmological constant term [10], higher dimensional collapse models [11][12][13][14], higher-order gravity theories [15], scalar field collapse [16][17][18][19][20], and self-similar collapse [21][22][23] (see also [2] for a recent review). Also, in the context of modified gravity theories, it is shown that naked singularities could form depending on different aspects of the theory (see, e.g., [24][25][26][27][28][29][30]).…”

Null Fluid Collapse in Rastall Theory of Gravity

“…Consequently, causal curves terminating in the past at the singularity have the chance to reach the faraway observers thus exposing super-dense regions of extreme gravity to the external universe. [10,11] In this context, formation of naked singularities as collapse outcome has been studied within many different scenarios such as gravitational collapse of a dust cloud, [12] scalar fields' collapse, [13][14][15][16][17][18][19] gravitational collapse in higher dimensions [20][21][22][23][24][25][26] etc. (for a review see refs.…”