  Exciton Valley Hall effect is the spatial separation of the valley-tagged
excitons in the presence of a drag force. Usually, the effect is associated
with the anomalous velocity acquired by the particles due to the Berry
curvature of the Bloch bands. Here we show that the anomalous velocity plays no
role in the exciton valley Hall effect, which is governed by the side-jump and
skew scattering mechanisms. We develop microscopic theory of the exciton valley
Hall effect in the presence of synthetic electric field and phonon drag and
calculate all relevant contributions to the valley Hall current also
demonstrating the cancellation of the anomalous velocity. The sensitivity of
the effect to the origin of the drag force and to the scattering processes is
shown. We extend the drift-diffusion model to account for the valley Hall
effect and calculate the exciton density and valley polarization profiles.
