String Theory and The Arrow of Time

Understand

Time-like linear dilaton triggers, at the classical level, the creation of closed folded strings at an instant.

• We show that in cosmology these instant folded strings induce negative pressure at no energy cost.
• Hence they seem to allow an era in which the energy density increases (decreases) while the universe is expanding (contracting).
• This and other aspects of instant folded strings suggest that they might shed new light on the origin of the arrow of time.