The dynamical behavior of $f(T)$ theory
  Recently, a new model obtained from generalizing teleparallel gravity, named
$f(T)$ theory, is proposed to explain the present cosmic accelerating expansion
with no need of dark energy. In this paper, we analyze the dynamical property
of this theory. For a concrete power law model, we obtain that the dynamical
system has a stable de Sitter phase along with an unstable radiation dominated
phase and an unstable matter dominated one. We show that the Universe can
evolve from a radiation dominated era to a matter dominated one, and finally
enter an exponential expansion phase.
