We study the following nonlinear fractional Choquard equation:
()
where
,
,
,
is the Riesz
potential with order
,
,
and
. By
specifying the ranges and interdependence of linear and nonlinear potentials, we achieve
the existence, convergence, concentration, and decay estimate of positive groundstates
for .
The multiplicity of semiclassical solutions is established via pseudoindex theory. The
existence of sign-changing solutions is constructed by minimizing the energy on
Nehari nodal set.