Nuts, bolts and spindles

We construct new infinite classes of Euclidean supersymmetric solutions of four-dimensional minimal gauged supergravity comprising a \(U (1) \times U (1)\)-invariant asymptotically locally hyperbolic metric on the total space of orbifold line bundles over a spindle (bolt). The conformal boundary is generically a squashed, branched, lens space, and the graviphoton gauge field can have either twist or anti-twist through the spindle bolt. Correspondingly, the boundary geometry inherits two types of rigid Killing spinors that we refer to as twist and anti-twist for the three-dimensional Seifert orbifolds, as well as some specific flat connections for the background gauge field, determined by the data of the spindle bolt. For all our solutions, we compute the holographically renormalized on-shell action and compare it to the expression obtained via equivariant localization, uncovering a markedly distinct behavior in the cases of twist and anti-twist. Our results provide precise predictions for the large N limit of the corresponding localized partition functions of three-dimensional \(\mathcal {N}=2\) superconformal field theories placed on Seifert orbifolds.