Hagedorn inflation of D-branes

TL;DR

This paper explores how the Hagedorn phase in D-brane models can induce various types of inflation and stabilize cosmological oscillations, offering insights into early universe dynamics without a cosmological constant.

Contribution

It demonstrates that winding modes during the Hagedorn phase can drive different inflationary behaviors and stabilize oscillating cosmologies in D-brane models.

Findings

Winding modes cause negative pressure leading to brane inflation.

Hagedorn phase can soften singularities during collapse.

Regimes of stable, oscillating universe identified.

Abstract

We examine the cosmological effects of the Hagedorn phase in models where the observable universe is pictured as a D-brane. It is shown that, even in the absence of a cosmological constant, winding modes cause a negative `pressure' that can drive brane inflation of various types including both power law and exponential. We also find regimes in which the cosmology is stable but oscillating (a bouncing universe) with the Hagedorn phase softening the singular behavior associated with the collapse.