de Sitter and Scaling solutions in a higher-order modified teleparallel
  theory
  The existence and the stability conditions for some exact relativistic
solutions of special interest are studied in a higher-order modified
teleparallel gravitational theory. The theory with the use of a Lagrange
multiplier is equivalent with that of General Relativity with a minimally
coupled noncanonical field. The conditions for the existence of de Sitter
solutions and ideal gas solutions in the case of vacuum are studied as also the
stability criteria. Furthermore, in the presence of matter the behaviour of
scaling solutions is given. Finally, we discuss the degrees of freedom of the
field equations and we reduce the field equations in an algebraic equation,
where in order to demonstrate our result we show how this noncanonical scalar
field can reproduce the Hubble function of $\Lambda$-cosmology.
