Spontaneous formation of double bars in dark matter dominated galaxies
  Although nearly one-third of barred galaxies host an inner, secondary bar,
the formation and evolution of double barred galaxies remain unclear. We show
here an example model of a galaxy, dominated by a live dark matter halo, in
which double bars form naturally, without requiring gas, and we follow its
evolution for a Hubble time. The inner bar in our model galaxy rotates almost
as slowly as the outer bar, and it can reach up to half of its length. The
route to the formation of a double bar may be different from that of a single
strong bar. Massive dark matter halo or dynamically hot stellar disc may play
an important role in the formation of double bars and their subsequent
evolution.
