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.