2012/02/13 by Marie-Françoise Bidaut-Véron, Bidaut-Véron, Marie-Françoise, Nguyen Anh Dao +1 · 1 citation
Mathematics · #Analysis of PDEs (math.AP) #FOS: Mathematics #math.AP
paper · pdf · doi:10.48550/arxiv.1202.2674
arxiv created 2013/03/22 · arxiv updated 2013/03/25
Here we study the nonnegative solutions of the viscous Hamilton-Jacobi problem \% ut-νΔu+|∇ u|q=0, u(0)=u0, . in QΩ,T=Ω×(0,T) , where q>1,ν\geqq 0,T∈(0,∞] , and Ω=ℝN or Ω is a smooth bounded domain, and u0∈ Lr(Ω),r\geqq1, or u0% \inMb(Ω). We show L∞ decay estimates, valid for any weak solution, without any conditions as ‖ x‖ →∞, and without uniqueness assumptions. As a consequence we obtain new uniqueness results, when u0∈ Mb(Ω) and q<(N+2)/(N+1), or u0∈ Lr(Ω) and q<(N+2r)/(N+r). We also extend some decay properties to quasilinear equations of the model type ut-Δpu+‖ u‖ λ-1u|∇ u|q=0 where p>1,λ\geqq0, and u is a signed solution.