F. Hirsch et Sq. Song, ON THE SET OF POSITIVITY OF THE DENSITY O F WIENER FUNCTIONALS, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 322(5), 1996, pp. 481-484
Let f be an R(d)-valued Wiener-functional, which is smooth and non-deg
enerate in the sense of the Malliavin calculus. Let p be the density,
with respect to the Lebesgue measure in R(d), Of its law. We are inter
ested in the set U = {p > 0} We prove, in particular, that U is a conn
ected set. A consequence is that the intrinsic distance associated wit
h f on U is a true distance (in particular; it is finite).