  A recent article (Khair and Kabarowski; Phys. Rev. Fluids 5, 033702) has
studied the cross-streamline migration of electrophoretic particles in
unbounded shear flows with weak inertia or viscoelasticity. That work compares
their results with those reported in two of our previous studies (Choudhary et
al.: J. Fluid Mech. 874; J. Fluid Mech. 898) and reports a disagreement in the
derived analytical expressions. In this comment, we resolve this discrepancy.
For viscoelastic flows, we show that Khair and Kabarowski have not accounted
for a leading order surface integral of polymeric stress in their calculation
of first-order viscoelastic lift. When this integral is included, the resulting
migration velocity matches exactly with that reported in our work (J. Fluid
Mech. 898). This qualitatively changes the migration direction that is reported
by Khair and Kabarowski for viscoelastic flows. For inertial flows, we clarify
that Khair and Kabarowski find the coefficient of lift to be 1.75$\pi$,
compared to 2.35$ \pi $ in our previous work (J. Fluid Mech. 874). We show that
this difference occurs because Khair and Kabarowski accurately include the
effect of rapidly decaying $ \sim O(1/r^{4}) $ velocity field (a correction to
the stresslet field $ \sim 1/r^{2} $), which was neglected in our previous work
(J. Fluid Mech. 874).
