4 - Cosmic censorship

Summary

As indicated here, the cosmic censorship hypothesis is fundamental to the basic theory and applications in blackhole physics. It follows from the previous considerations that the cosmic censorship, if it does hold, is not valid in any obvious and plain manner in general relativity, but it has to be carefully designed and formulated. This is important for any clear basis and foundation for blackhole physics. As yet, such a mathematical formulation is not available, and much work is needed to achieve one. In such a case, the existence and formation of blackholes as the final state of a gravitational collapse, whenever a massive star collapses in the universe on exhausting its nuclear fuel, cannot be taken as automatic.

Basically, cosmic censorship is a statement about the causal structure of spacetime, as related to the dynamical collapse scenarios that are fundamental processes in astrophysics and cosmology. Therefore, in this chapter, which aims to discuss various aspects related to the censorship conjecture and its possible formulations, are considered in Section 4.1 some basic aspects of the causal structure of spacetime. The physics related to gravity becomes much more important in situations such as gravitational collapse and those of the early universe phases in cosmology. The general theory of relativity predicts the occurrence of spacetime singularity in such situations, which are the extreme gravity regions where densities, spacetime curvatures, and other physical quantities take extreme values. The quantum gravity effects would become much more prominent in such regions.