N=1 SCFTs from F-theory on Orbifolds

We study four-dimensional superconformal field theories living on the worldvolume of $D3$ branes probing minimally-supersymmetric F-theory backgrounds, focusing on the case of orbi-orientifold setups with and without 7-branes. We observe that these theories are closely related to compactifications of six-dimensional $\mathcal{N}=(1,0)$ theories on a torus with flux, where the flux quanta is mapped in Type IIB to the defining data of the orbifold group. We analyze the cases of class ${\mathcal{S}}_k$ theories as well as of compactifications of the E-string and of orbi-instanton theories. We also classify $\mathcal{S}$-fold configurations in F-theory preserving minimal supersymmetry in four dimensions and their mass deformations.