On the Nature of Exotic Matter in Morris-Thorne Wormholes

Abstract

It is well known that phantom energy, which is characterized by the equation of state p = ωρ, ω < −1, can support Morris-Thorne wormholes since it leads to a violation of the null energy condition. The purpose of this note is to show that the converse is also true in the following sense: for a typical shape function, the equation of state of exotic matter in the vicinity of the throat is given by p↓r = ωρ, ω < −1, where pr is the radial pressure.