QCD Axion and Dark Energy

TL;DR

This paper explores the connections between string theory's discrete symmetries, the QCD axion, dark energy, and inflation, discussing their implications and recent observational data.

Contribution

It proposes a framework linking string-derived symmetries to solutions for dark energy and the QCD axion, incorporating recent BICEP2 results.

Findings

Discussions on how string symmetries influence low-energy effective theories.

Implications of BICEP2 data for inflation models.

Potential connections between axion physics and dark energy.

Abstract

String allowed discrete symmetry is the mother of acceptable effective global symmetries at low energy. With this philosophy, we discuss dark energy, QCD axion, and inflation, and speculate some implications of the recent BICEP2 data.