Dimensional reduction of higher derivative heterotic supergravity

A bstract Higher derivative couplings of hypermultiplets to 6 D, N = (1 , 0) supergravity are obtained from dimensional reduction of 10D heterotic supergravity that includes order α ′ higher derivative corrections. Reduction on T 4 is followed by a consistent truncation. In the resulting action the hyperscalar fields parametrize the coset SO(4 , 4) / (SO(4) × SO(4)). While the SO(4 , 4) symmetry is ensured by Sen’s construction based on string field theory, its emergence at the field theory level is a nontrivial phenomenon. A number of field redefinitions in the hypermultiplet sector are required to remove several terms that break the SO(4) × SO(4) down to its SO(4) diagonal subgroup in the action and the supersymmetry transformation rules. Working with the Lorentz Chern-Simons term modified 3-form field strength, where the spin connection has the 3-form field strength as torsion, is shown to simplify considerably the dimensional reduction.