It is well known that the composition operator
is unbounded on Hardy and Bergman spaces on the unit ball
in
when
for a linear
holomorphic self-map
of
. We find
a sufficient and necessary condition for a composition operator with smooth symbol to
be bounded on Hardy or Bergman spaces over a bounded strictly pseudoconvex domain
in
.
Moreover, we show that this condition is equivalent to the compactness of the
composition operator from a Hardy or Bergman space into the Bergman space whose
weight is
bigger. We also prove that a certain jump phenomenon occurs when the composition
operator is not bounded. Our results generalize known results on the unit ball to
strictly pseudoconvex domains.
Keywords
composition operator, strictly pseudoconvex domain,
boundedness, smooth symbol