Given an
-dimensional
compact Riemannian manifold
without boundary, we consider the nonlocal equation
where
stands for the fractional Paneitz operator with principal symbol
,
,
with
,
, represents the critical
Sobolev exponent and
is a small real parameter. We construct a family of positive solutions
that
concentrate, as
goes to zero, near critical points of the mean curvature
for
and near
critical points of a reduced function involving the scalar curvature of the manifold
for
.