Towards a Dark Sector Model from String Theory

TL;DR

This paper proposes a string theory-based dark sector model where the axion acts as dark matter and a Kähler modulus accounts for dark energy, with stabilization mechanisms and potential tuning to match previous models.

Contribution

It embeds a unified dark sector model into string theory, identifying specific fields with dark matter and dark energy components, and demonstrates stabilization and potential tuning.

Findings

Axion identified as dark matter field

Kähler modulus accounts for dark energy

Stabilization of the dilaton field achieved

Abstract

An embedding of a unified dark sector model into string theory with the following features is proposed: The model-independent axion descending from the Kalb-Ramond 2-form field is identified with the dark-matter field, and the real part of a K\"ahler modulus field -- the ``radius'' of one of the extra spatial dimensions -- accounts for dark energy. The expectation value of the dilaton field is stabilized by a gaugino condensation mechanism. A dark-energy potential corresponding to a realistic low energy scale results from some gentle tuning of the stabilized expectation value of the dilaton. The resulting potential reproduces the one in a previous dark-sector model proposed by two of us.