@Article{ mirpalpar06, author = { Miranda Jr, Michele and Pallara, Diego and Paronetto, Fabio and Preunkert, Marc }, title = { On a characterisation of perimeters in $\Bbb R^N$ via heat semigroup }, journal = { Ricerche Mat. }, year = { 2006 }, volume = { 54 }, number = { 2 }, pages = { 615-621 }, URL = { http://cvgmt.sns.it/paper/1600/ }, note = { cvgmt preprint} }