TY - JOUR T1 - Gaussian estimates for hypoelliptic operators via optimal control JF - Atti Accad. Naz. Lincei Cl. Sci. Fis. Mat. Natur. Rend. Lincei (9) Mat. Appl. 18 (2007) 333-342 Y1 - 2007 A1 - Ugo Boscain A1 - Sergio Polidoro AB - We obtain Gaussian lower bounds for the fundamental solution of a class of hypoelliptic equations, by using repeatedly an invariant Harnack inequality. Our main result is given in terms of the value function of a suitable optimal control problem. UR - http://hdl.handle.net/1963/1994 U1 - 2202 U2 - Mathematics U3 - Functional Analysis and Applications ER -