Gravitational collapse of inhomogeneous dust: Naked singularities, black hole formation and Hawking evaporation

Abstract

There are several examples of existence of naked singularities in models of spherically symmetric gravitational collapse and they are considered to be counter-examples to the Cosmic Censorship (CCC). In fact, there were suggestions and attempts to realize energy output in the form of gamma ray bursts or particle production near the strong naked singularities. We have argued that the counter-examples cited are physically unrealistic and therefore they do not violate a realistic CCC. This also means that attempts to model them as high energy sources are unrealistic. However, we point out that there is a possibility of formation of black holes of mass small enough for quantum Hawking evaporation to become important, in inhomogeneous collapse. But estimate of the energy output and other physical considerations like the need for fine tuning show that it is too speculative to invoke them in any realistic astrophysical situation.