We construct maximal supergravity in four dimensions with local scaling symmetry as deformation of the original Cremmer-Julia theory. The different theories which include the standard gaugings are parametrized by an embedding tensor carrying 56+912 p
arameters. We determine the form of the possible gauge groups and work out the complete set of field equations. As a result we obtain the most general couplings compatible with N=8 supersymmetry in four dimensions. A particular feature of these theories is the absence of an action and an additional positive contribution to the effective cosmological constant. Moreover, these gaugings are generically dyonic, i.e. involve simultaneously electric and magnetic vector fields.
We present a systematic account of supergravity theories in which the global scaling symmetry is gauged. This generalizes the standard gaugings of non-abelian off-shell symmetries. A particular feature of these theories is an additional positive cont
ribution to the effective cosmological constant. As the scaling symmetry is an on-shell symmetry, the resulting gaugings do no longer possess an action. We develop the algebraic framework for the maximal theories in various dimensions and construct explicit solutions to the algebraic consistency constraints - related to `pure-spinor-like structures for the exceptional groups. As an example, we explicitly work out the modified supersymmetry transformation rules and equations of motion in three dimensions. Finally, we speculate about the role of these theories from the perspective of very extended Kac-Moody algebras.
