The Landscape of M-theory Compactifications on Seven-Manifolds with $G_2$ Holonomy

TL;DR

This paper explores the physics of M-theory compactifications on $G_2$ manifolds, focusing on a specific example with rich gauge symmetry, instanton effects, and topology transitions, providing insights into the $G_2$ landscape.

Contribution

It presents a detailed analysis of a $G_2$ compactification with $U(1)^3$ symmetry, including instanton corrections and topology change, advancing understanding of the $G_2$ landscape and its physical implications.

Findings

Membrane instanton corrections computed for the superpotential.

Topology change includes $G_2$ flop and conifold transitions.

Gauge symmetry is spontaneously broken during conifold transition.

Abstract

We study the physics of globally consistent four-dimensional $\mathcal{N}=1$ supersymmetric M-theory compactifications on $G_2$ manifolds constructed via twisted connected sum; there are now perhaps fifty million examples of these manifolds. We study a rich example that exhibits $U(1)^3$ gauge symmetry and a spectrum of massive charged particles that includes a trifundamental. Applying recent mathematical results to this example, we compute membrane instanton corrections to the superpotential and spacetime topology change in a compact model; the latter include both the (non-isolated) $G_2$ flop and conifold transitions. The conifold transition spontaneously breaks the gauge symmetry to $U(1)^2$, and associated field theoretic computations of particle charges make correct predictions for the topology of the deformed $G_2$ manifold. We discuss physical aspects of the abelian $G_2$ landscape broadly, including aspects of Higgs and Coulomb branches, membrane instanton corrections, and some general aspects of topology change.