Spin connection and cosmological perturbations in scalar-torsion gravity.

In this paper, we generalize our previous results on spin connection for the linear scalar cosmological perturbation in f (T) theory to a wider class of theories which includes a scalar field Φ non-minimally coupled to torsion, and allows Φ -dependence of the function f. The case of f T T = 0 , with a scalar field non-minimally coupled to torsion, needs a special treatment. In both considered cases we derive self-consistent equations of motion for cosmological perturbation using a solution for non-trivial spin connection. [ABSTRACT FROM AUTHOR]