Non-standard embedding and five-branes in heterotic M-Theory

TL;DR

This paper constructs M-theory vacua with five-branes and general gauge bundles on Calabi-Yau spaces, revealing new gauge symmetry patterns and modifications to low-energy physics due to five-branes.

Contribution

It introduces a framework for incorporating five-branes and general gauge bundles in heterotic M-theory compactifications, expanding the landscape of possible low-energy theories.

Findings

Enlarged gauge groups from five-brane world-volumes

New E8 x E8 breaking patterns enabled by five-branes

Modified threshold corrections to gauge kinetic functions

Abstract

We construct vacua of M-theory on S^1/Z_2 associated with Calabi-Yau three-folds. These vacua are appropriate for compactification to N=1 supersymmetry theories in both four and five dimensions. We allow for general E_8 x E_8 gauge bundles and for the presence of five-branes. The five-branes span the four-dimensional uncompactified space and are wrapped on holomorphic curves in the Calabi-Yau space. Properties of these vacua, as well as of the resulting low-energy theories, are discussed. We find that the low-energy gauge group is enlarged by gauge fields that originate on the five-brane world-volumes. In addition, the five-branes increase the types of new E_8 x E_8 breaking patterns allowed by the non-standard embedding. Characteristic features of the low-energy theory, such as the threshold corrections to the gauge kinetic functions, are significantly modified due to the presence of the five-branes, as compared to the case of standard or non-standard embeddings without five-branes.