Massive black holes: dynamics, spin evolution and gravitational wave
detection

Within this decade the detection of gravitational waves (GWs) may be a
reality, opening a completely new window on the Universe. The low
frequency window will be dominated by signals emitted by a
cosmological population of massive black hole binaries (MBHBs). In
this talk I will review several aspect of MBH physics focusing in
particular on spin evolution and gravitational wave emission. In the
first part of the talk, I will present a model linking the accretion
flow to the kinematical properties of the galaxy hosts, which produces
MBH spins in broad agreement with current observations. In the second
part, I will pay particular attention to the prospect of GW detection
from MBHBs with pulsar timing arrays and/or future space based
interferometers.