In the business of writing my master thesis about the possible treatment of naked singularities with canonical quantization I encountered a lot of papers of Pankaj S. Joshi, who is a theoretical physics at the Tata Institute of Fundamental Research in Mumbai, India. He is an expert in the field of general relativity and cosmology with a big interest in the fascinating topic of dynamical collapse scenarios.
Since I started my master thesis only some month ago and I am completely new in this field I looked around for some references that treat gravitational collapses and their outcomes, i.e. black holes and naked singularities, at a very broad sense. In January of this year Prof. Joshi published his book 'the story of collapsing stars' via the Oxford University Press. In order to get more knowledge about my kind of research I decided to read his book and now, finally, I finished an want to give a little review.
Before betting into detail I want to sum up my impression about the book: Overall his book quite nice to read and most notably very comprehensible. For everyone who is interested in topic concerning the formation of stars I would really recommend this book to read.
The first chapter of the book has the title 'our universe' and concerns the role of gravity in the evolution of our universe. In particular this is were the reader meets the word 'singularity' for the first time. In the following three chapters we makes these concepts more concrete and talks also about problems that arise from these concepts. Most importantly he points at the problem of the so-called cosmic censorship conjecture(CCC) which states that every gravitational collapse of reasonable initial conditions should result in a black hole, i.e. a singularity that is covered by an event horizon that forbids and interaction the to far away part of the universe. In other words, this conjecture would rule out the existence of so-called naked singularities. The mathematical problems of defining such a theorem or conjecture are pointed out and explained. The conclusion was made that only the study of different types of collapsing scenarios can give us a hint whether the CCC is right has to be thrown away.
He also explains that a star under reasonable initial conditions will more likely end up as a naked singularity instead of a black hole. After this statement has been made he explains various other types and models of gravitational collapses and points out that naked singularities are as common as black holes. This makes it, of course, difficult to write down an explicit form of the CCC.
In the last parts of his book he explains how naked singularities affect the structure of spacetime and discusses some phenomena that might be observed to distinguish between a naked singularity and a black hole.