Brany Liouville Inflation

TL;DR

This paper proposes a string theory-based inflation model driven by the Liouville field, connecting brane dynamics with cosmological observations and suggesting a small, evolving vacuum energy component.

Contribution

It introduces a novel inflationary model using non-critical supersymmetric string theory with brane dynamics, constrained by cosmic microwave background and gamma-ray burst data.

Findings

Model parameters fixed by WMAP data

Consistent with gamma-ray burst light propagation constraints

Suggests a small, relaxing vacuum energy component

Abstract

We present a specific model for cosmological inflation driven by the Liouville field in a non-critical supersymmetric string framework, in which the departure from criticality is due to open strings stretched between the two moving Type-II 5-branes. We use WMAP and other data on fluctuations in the cosmic microwave background to fix parameters of the model, such as the relative separation and velocity of the 5-branes, respecting also the constraints imposed by data on light propagation from distant gamma-ray bursters. The model also suggests a small, relaxing component in the present vacuum energy that may accommodate the breaking of supersymmetry.