Free Fisher information of a self-adjoint tuple
in a von Neumann algebra with a faithful normal
tracial state
is
where vectors
satisfy
for every noncommutative polynomial . Here
, and
is the derivation
determined by
and the product rule. These vectors lie in the
completion
of the algebra generated by the tuple. When they do not
exist,
. Integrating this quantity along addition
of freely independent semicircular
noise defines nonmicrostates free entropy.