Trombone gaugings of five-dimensional maximal supergravity

The maximal gauged supergravities in five spacetime dimensions with gauge groups contained in $\mathbb{R}^+ \times \textrm{E}_{6(6)}$ are described. The $\textrm{E}_{6(6)}$ factor is the duality group of ungauged maximal supergravity and $\mathbb{R}^+$ is the scaling symmetry of the five-dimensional metric, usually called the \textit{trombone} symmetry. The equations of motion and supersymmetry variations for these supergravities are given to lowest order in fermions, and the mass matrices are provided. Then, the theories with gauge groups contained in a maximal subgroup of $\mathbb{R}^+ \times \textrm{E}_{6(6)}$ are classified, and a new family of such supergravities uncovered. For a concrete theory in this class, some supersymmetric anti-de Sitter vacua are found and their mass spectra computed within the gauged supergravity. These vacua are argued to be related to superconformal phases of the M5-brane field theory.