Secular evolution and pseudo-bulges
  Through vertical resonances, bars can produce pseudo-bulges, within secular
evolution. Bulges and pseudo-bulges have doubled their mass since z=1. The
frequency of bulge-less galaxies at z=0 is difficult to explain, especially
since clumpy galaxies at high z should create classical bulges in all galaxies.
This issue is solved in modified gravity models. Bars and spirals in a galaxy
disk, produce gravity torques that drive the gas to the center and fuel central
star formation and nuclear activity.
  At 0.1-1kpc scale, observations of gravity torques show that only about one
third of Seyfert galaxies experience molecular inflow and central fueling,
while in most cases the gas is stalled in resonant rings. At 10-20pc scale,
some galaxies have clearly revealed
  AGN fueling due to nuclear trailing spirals, influenced by the black hole
potential.
  Thanks to ALMA, and angular resolution of up to 80mas it is possible to reach
the central black hole (BH) zone of influence, discover molecular tori,
circum-nuclear disks misaligned with the galaxy, and the BH mass can be derived
more directly from the kinematics.
