  The absorption cross section is studied in the low-frequency region for a
propagating scalar field under the warped AdS$_3$ black hole background in the
topologically massive gravity. It can be shown that the absorption cross
section is significantly deformed by the gravitational Chern-Simons term, which
is proportional to the scattering area of black hole with an additional
contribution depending on the left-moving and right-moving temperatures. It
means that the cross section is larger than the area in spite of the s-wave
limit. Finally, we discuss the left-right quasinormal modes for the scalar
perturbation in this black hole.
