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Regularity of solutions of the fractional porous medium flow

Luis Caffarelli, Fernando Soria, Juan Luis Vázquez (2013)

Journal of the European Mathematical Society

We study a porous medium equation with nonlocal diffusion effects given by an inverse fractional Laplacian operator. The precise model is u t = · ( u ( - Δ ) - s u ) , 0 < s < 1 . The problem is posed in { x n , t } with nonnegative initial data u ( x , 0 ) that are integrable and decay at infinity. A previous paper has established the existence of mass-preserving, nonnegative weak solutions satisfying energy estimates and finite propagation. As main results we establish the boundedness and C α regularity of such weak solutions. Finally, we extend the existence...

Renormalized solution for nonlinear degenerate problems in the whole space

Mohamed Maliki, Adama Ouedraogo (2008)

Annales de la faculté des sciences de Toulouse Mathématiques

We consider the general degenerate parabolic equation : u t - Δ b ( u ) + d i v F ˜ ( u ) = f in Q = ] 0 , T [ × N , T &gt; 0 . We suppose that the flux F ˜ is continuous, b is nondecreasing continuous and both functions are not necessarily Lipschitz. We prove the existence of the renormalized solution of the associated Cauchy problem for L 1 initial data and source term. We establish the uniqueness of this type of solution under a structure condition F ˜ ( r ) = F ( b ( r ) ) and an assumption on the modulus of continuity of b . The novelty of this work is that Ω = N , u 0 , f L 1 , b , F ˜ are not Lipschitz...

Singular Perturbations for a Class of Degenerate Parabolic Equations with Mixed Dirichlet-Neumann Boundary Conditions

Marie-Josée Jasor, Laurent Lévi (2003)

Annales mathématiques Blaise Pascal

We establish a singular perturbation property for a class of quasilinear parabolic degenerate equations associated with a mixed Dirichlet-Neumann boundary condition in a bounded domain of p , 1 p &lt; + . In order to prove the L 1 -convergence of viscous solutions toward the entropy solution of the corresponding first-order hyperbolic problem, we refer to some properties of bounded sequences in L together with a weak formulation of boundary conditions for scalar conservation laws.

Currently displaying 301 – 320 of 415