String Theory and The Arrow of Time

TL;DR

This paper explores how instant folded strings in string theory could influence the universe's expansion and contraction, potentially offering insights into the origin of the arrow of time.

Contribution

It introduces the concept that instant folded strings induce negative pressure in cosmology, providing a novel perspective on the arrow of time within string theory.

Findings

Instant folded strings create negative pressure at no energy cost.

They can cause the universe's energy density to increase during expansion.

They may shed light on the origin of the arrow of time.

Abstract

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.