Gravitational Collapse of Dust Cloud with Dark Energy

In this paper, we have investigated the gravitational collapse of a spherically symmetric star with anisotropic pressure, made of a dust fluid and dark energy with equations of state p (t) =w rho and p (r) =k rho, {(k+2w)<-1}. We have considered three cases. First with dust cloud, the second with dark energy and the third with both dust cloud and dark energy without interaction. The effects of dark energy on the gravitational collapse has been studied. It is found that when only dark energy is present, black hole can never be formed. When both dust cloud and dark energy are present, a black hole is formed. This work provides a generalization of the work by Cai and Wang for isotropic pressure to anisotropic pressure (Cai and Wang in Phys. Rev. D 73:063005, 2006).