New classes of modified teleparallel gravity models

Understand

New classes of modified teleparallel theories of gravity are introduced.

• The action of this theory is constructed to be a function of the irreducible parts of torsion $f(T_{\rm ax},T_{\rm ten},T_{\rm vec})$, where $T_{\rm ax},T_{\rm ten}$ and $T_{\rm vec}$ are squares of the axial, tensor and vector components of torsion, respectively.
• This is the most general (well-motivated) second order teleparallel theory of gravity that can be constructed from the torsion tensor.
• Different particular second order theories can be recovered from this theory such as new general relativity, conformal teleparallel gravity or $f(T)$ gravity.