We consider the Calogero–Sutherland derivative nonlinear Schrödinger equation in the focusing (with
sign
) and defocusing
case (with sign
)
where
is the
Szegő projector
.
Thanks to a Lax pair formulation, we derive the
explicit solution to
this equation. Furthermore, we prove the
global well-posedness for this
-critical equation in all the
Hardy Sobolev spaces
,
, with small
-initial data in the focusing
case, and for arbitrarily
-data
in the defocusing case. In addition, we establish the relative compactness of the trajectories
in all
,
.