Positivity and lower bounds for the density of Wiener functionals
نویسندگان
چکیده
We consider a functional on the Wiener space which is smooth and not degenerated in Malliavin sense and we give a criterion for the strict positivity of the density, that we can use to state lower bounds as well. The results are based on the representation of the density in terms of the Riesz transform introduced in Malliavin and Thalmaier bib:[M.T] [16] and on the estimates of the Riesz transform given in Bally and Caramellino bib:[B.C] [3].
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