  We show that the universal odd Chern form, defined on the stable unitary
group $U$, extends to the loop group $LU$ in a way that is closed with respect
to an equivariant-type differential. This provides an odd analogue to the
Bismut-Chern form. We also describe the associated transgression form, the
so-called Bismut-Chern-Simons form, and explicate some properties it inherits
as a differential form on the space of maps of a cylinder into the stable
unitary group. As a corollary, we obtain the Chern character homomorphism from
odd K-theory to the periodic cohomology of the free loop space, represented
geometrically on the level of differential forms.
