Quasilinear elliptic Hamilton-Jacobi equations on complete manifolds

Abstract

Let (M^n,g) be a n-dimensional complete, non-compact and connected Riemannian manifold, with Ricci tensor Ricc_g and sectional curvature Sec_g. Assume Ricc_g\geq (1-n)B^2, and either p>2 and Sec_g(x)=o(dist^2(x,a)) when dist^2(x,a)\to\infty for a\in M, or 1<p<2 and Sec_g(x)\leq 0. If q>p-1> 0, any C^1 solution of (E) -\Gd_pu+\abs{\nabla u}^q=0 on M satisfies \abs{\nabla u(x)}\leq c_{n,p,q}B^{\frac{1}{q+1-p}} for some constant c_{n,p,q}>0. As a consequence there exists c_{n,p}>0 such that any positive p-harmonic function v on M satisfies v(a)e^{-c_{n,p}B\dist (x,a)}\leq v(x)\leq v(a)e^{c_{n,p}B\dist (x,a)} for any (a,x)\in M\times M.