Charging Symmetries and Linearizing Potentials for Gravity Models with Symplectic Symmetry

摘要

In this letter we continue to study a class of four-dimensional gravity models with n Abelian vector fields and Sp(2n, R)/U(n) coset of scalar fields. This class contains General Relativity (n = 0) and Einstein-Maxwell dilaton axion theory (n = 1), which arises in the low energy limit of heterotic string theory. We perform reduction of the model with arbitrary n to three dimensions and study the subgroup of non-gauge symmetries of the resulting theory. First, we find an explicit form these symmetries using the Ernst matrix potential formulation. Second, we construct a new matrix variable which linearly transforms under the action of the non-gauge transformations. Finally, we establish one general invariant of the non gauge symmetry subgroup, which allows us to clarify this subgroup structure.