Cosmic censorship and the role of pressure in gravitational collapse

Assuming the weak energy condition, we study the nature of the non-central shell-focusing singularity which can form in the gravitational collapse of a spherical compact object in classical general relativity. We show that if the radial pressure is positive, the singularity is covered by a horizon. For negative radial pressures, the singularity will be covered if the ratio of pressure to the density is greater than -1/3 and naked if this ratio is less than or equal to -1/3.