Some properties of the 'string gas' with the equation of state p = -1/3ρ

摘要

We show that the string gas a perfect fluid with the equation of state p = -1/3ρ possesses rather interesting properties. In Friedmann universes its presence can change the observable topology of the space; in the spherically symmetric spacetimes it produces rather bizzare geometries and in a way its influence on the rotation curves mimics the dark matter effects.