Conformal symmetry and accelerating cosmology in teleparallel gravity

We discuss conformal issues of pure and extended teleparallel gravity. In particular, we present formulations of conformal transformation in teleparallel gravity. Furthermore, we propose conformal scalar and gauge field theories in teleparallel gravity and study conformal torsion gravity. We explicitly demonstrate that a power-law acceleration (including the ΛCDM universe) as well as the de Sitter expansion of the Universe can be realized in extended teleparallel gravity with a conformal scalar field, and that pure teleparallel gravity with a conformal scalar field can lead to the ΛCDM model. It is also shown that the de Sitter solution can exist in conformal torsion gravity.