Janus and Hades in M-theory

Multi-parametric and analytic families of four-dimensional AdS₃ × ℝ (Janus) and AdS₃ × ℝ⁺ (Hades) solutions are constructed in the SO(8) gauged supergravity that arises from the consistent reduction of eleven-dimensional supergravity on S⁷. The solutions are generically non-supersymmetric, involve non-trivial running scalars and preserve a U(1)⁴ symmetry. Different patterns of (super) symmetry enhancement occur upon suitable adjustment of the free parameters which further control the boundary conditions of the running scalars. We concentrate on the non-supersymmetric Janus and Hades solutions with SU(3) × U(1)² symmetry and provide their higher-dimensional description in terms of M-theory fluxes and membranes. Special attention is paid to a class of such Hades solutions dubbed “ridge flows” which resemble dielectric rotations of Coulomb branch flows previously investigated in the literature.