We present maximal supergravity in two dimensions with gauge group SO(9). The construction is based on selecting the proper embedding of the gauge group into the infinite-dimensional symmetry group of the ungauged theory. The bosonic part of the Lagrangian is given by a (dilaton-)gravity coupled non-linear gauged σ-model with WessZumino term. We give explicit expressions for the fermionic sector, the Yukawa couplings and the scalar potential which supports a half-supersymmetric domain wall solution. The theory is expected to describe the low-energy effective action upon reduction on the D0-brane near-horizon warped AdS 2 ×S 8 geometry, dual to the supersymmetric (BFSS) matrix quantum mechanics.

The fluctuations around the D0-brane near-horizon geometry are described by two-dimensional SO(9) gauged maximal supergravity. We work out the U(1)^4 truncation of this theory whose scalar sector consists of five dilaton and four axion fields. We construct the full non-linear Kaluza-Klein ansatz for the embedding of the dilaton sector into type IIA supergravity. This yields a consistent truncation around a geometry which is the warped product of a two-dimensional domain wall and the sphere S^8. As an application, we consider the solutions corresponding to rotating D0-branes which in the near-horizon limit approach AdS2xM8 geometries, and discuss their thermodynamical properties. More generally, we study the appearance of such solutions in the presence of non-vanishing axion fields.Comment: 16 pages, no figure