摘要We attempt to discover some exact analytical models of the spherically symmetric spacetime of collapsing fluid under shearfree conditions. Two types of solution are considered: one is to impose a condition on the mass function, while the other is to restrict the pressure. We obtain five exact models in total, and some of them satisfy the Darmois conditions.
Abstract：We attempt to discover some exact analytical models of the spherically symmetric spacetime of collapsing fluid under shearfree conditions. Two types of solution are considered: one is to impose a condition on the mass function, while the other is to restrict the pressure. We obtain five exact models in total, and some of them satisfy the Darmois conditions.
2012, Vol. 29 
