  Dynamics of active deformable particles in an external Poiseuille flow is
investigated. In order to make the analysis general, we employ time-evolution
equations derived from symmetry considerations that take into account an
elliptical shape deformation. First, we clarify the relation of our model to
that of rigid active particles. Then, we study the dynamical modes that active
deformable particles exhibit by changing the strength of the external flow. We
emphasize the difference between the active particles that tend to self-propel
parallel to the elliptical shape deformation and those self-propelling
perpendicularly. In particular, a swinging motion around the centerline far
from the channel walls is discussed in detail.
