Kavli Affiliate: Jeffrey A. Harvey | First 5 Authors: Jeffrey A. Harvey, Tai Wai Hu, , , | Summary: Compactification of heterotic string on a Calabi-Yau threefold can lead to a four-dimensional low-energy effective theory which contains a $U(1)$ gauge theory which is pseudo-anomalous, meaning that the fermion content is anomalous, but that the fermion […]