  It is commonly assumed that in black hole accretion disks the angular momenta
of the disk and the black hole are aligned. However, for a significant fraction
of stellar mass black holes and supermassive black holes, the momenta may not
be aligned. In such systems, the interplay of disk viscosity and general
relativistic frame dragging can cause the disk to warp or break into two (or
more) distinct planes; this is called the Bardeen-Petterson effect. We have
developed a general relativistic ray-tracing code to find the energy spectra
and polarization of warped accretion disks, accounting for the emission from
the disk and for photons reflecting one or multiple times off the warped
accretion disk segments. We find that polarization angle can be used to give a
lower limit on the misalignment angle when a previous measurement of the jet,
which is thought be aligned with the black hole angular momentum, can be
spatially resolved.
