Collapsing fluid with self-similarity of the second kind in 2+1 gravity

摘要

Anisotropic fluid with self-similarity of the second kind in (2 + 1)-dimensional space times with circular symmetry is studied. By imposing the condition that the radial pressure vanishes, we show that the only allowed solutions are the ones that represent dust fluid. All such solutions to the Einstein field equations are found and their local and global properties are studied in detail. It is found that some can be interpreted as representing gravitational collapse, in which both naked singularities and black holes can be formed.