Nonlinear diffusions, hypercontractivity and the optimal Lp-Euclidean logarithmic Sobolev inequality Manuel DEL PINO a Jean DOLBEAULT b,2,? Ivan GENTIL c aDepartamento de Ingenierıa Matematica, F.C.F.M., Universidad de Chile, Casilla 170 Correo 3, Santiago, Chile bCeremade (UMR CNRS no. 7534), Universite Paris IX-Dauphine, Place de Lattre de Tassigny, 75775 Paris Cedex 16, France cLaboratoire de statistique et probabilites, (UMR CNRS no. 5583), Universite Paul-Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 4, France Abstract The equation ut = ∆p(u1/(p?1)) for p > 1 is a nonlinear generalization of the heat equation which is also homogeneous, of degree 1. For large time asymptotics, its links with the optimal Lp-Euclidean logarithmic Sobolev inequality have recently been investigated. Here we focuse on the existence and the uniqueness of the solutions to the Cauchy problem and on the regularization properties (hypercontractivity and ultracontractivity) of the equation using the Lp-Euclidean logarithmic Sobolev inequality. A large deviation result based on a Hamilton-Jacobi equation and also related to the Lp-Euclidean logarithmic Sobolev inequality is then stated. Key words: Optimal Lp-Euclidean logarithmic Sobolev inequality, Sobolev inequality, nonlinear parabolic equations, degenerate parabolic problems, entropy, existence, Cauchy problem, uniqueness, regularization, hypercontractivity, ultracontractivity, large deviations, Hamilton-Jacobi equations AMS classification (2000).
- hamilton- jacobi equation
- lp-euclidean logarithmic
- main results
- sobolev inequality
- associated semi-group
- optimal lp-euclidean logarithmic