f ( T ) theories and varying fine structure constant

摘要

In analogy tof(R)theory, recently a new modified gravity theory, namely the so-calledf(T)theory, has been proposed to drive the current accelerated expansion without invoking dark energy. In the present work, by extending Bisabr?s idea, we try to constrainf(T)theories with the varying fine structure “constant”,α≡e2/?c. We find that the constraints onf(T)theories from the observationalΔα/αdata are very severe. In fact, they makef(T)theories almost indistinguishable from ΛCDM model.