Cosmological dynamics of tachyonic teleparallel dark energy

A detailed dynamical analysis of the tachyonic teleparallel dark energy model, in which a noncanonical scalar field (tachyon field) is nonminimally coupled to gravitation, is performed. It is found that, when the nonminimal coupling is ruled by a dynamically changing coefficient $\alpha \equiv f_{,\varphi }/\sqrt{f}$, with $f(\varphi )$ an arbitrary function of the scalar field $\varphi$, the Universe may experience a field-matter-dominated era “$\varphi \mathrm{MDE}$,” in which it has some portions of the energy density of $\varphi$ in the matter dominated era. This is the most significant difference in relation to the so-called teleparallel dark energy scenario, in which a canonical scalar field (quintessence) is nonminimally coupled to gravitation.