The Relic Problem of String Gas Cosmology

Understand

We discuss the relic problem of string gas cosmology (SGC) using gravitinos and magnetic monopoles as examples.

• Since SGC operates near or at the Hagedorn temperature, relics are produced copiously; in the absence of dilution, their abundances are too large.
• A subsequent phase of reheating can solve the gravitino problem, but fails to dilute monopoles sufficiently.
• We propose a subsequent phase of inflation as the most natural solution to the monopole problem; unfortunately, inflation marginalizes almost all potential achievements of SGC, with the exception of a possible explanation of the dichotomy of space (why did only three dimensions inflate?).