f(R) gravity with spacetime torsion

The duality between a higher-curvature f (R) gravity model and a scalar-tensor theory helps to bring out the role of the additional degree of freedom originating from the higher-derivative terms in the gravity action. Such a degree of freedom which appears as a scalar field has been shown to have multiple implications in the cosmological/astrophysical scenario. The present work proposes a novel generalization to this correspondence between f (R) gravity and a dual scalar- tensor theory when the affine connection is considered to have an antisymmetric part. It turns out that the f (R) action in the presence of spacetime torsion can be recast to a non- minimally coupled scalar-tensor theory with a 2-rank massless antisymmetric tensor field in the Einstein frame, where the scalar field gets coupled with the antisymmetric field through derivative coupling(s).