Spin(7) metrics of cohomogeneity one with Aloff--Wallach spaces as principal orbits

Abstract: In this article, we construct two continuous 1-parameter family of non-compact $\mathrm{Spin}(7)$ metrics with both chiralities, with the principal orbit an Aloff--Wallach space $N_{k,l}$ and the singular orbit $\mathbb{CP}^2$. For generic $N_{k,l}$, metrics constructed are locally asymptotically conical (ALC). For $N_{1,1}$, we construct two continuous 1-parameter families with geometric transition from asymptotically conical (AC) metrics to ALC metrics.