Asymptotic behavior at infinity and existence of solutions to the Lagrangian mean curvature flow in $\mathbb R^{n+1}_-$
Jiguang Bao, Zixiao Liu
TL;DR
This work analyzes ancient solutions to the Lagrangian mean curvature flow in $\mathbb{R}^{n+1}_-$ with compactly supported forcing $f$, establishing Liouville-type rigidity that forces asymptotic behavior to a quadratic form in space plus a linear term in time, with an explicit exponential convergence rate. It also constructs a global viscosity solution with prescribed infinity behavior for all dimensions $n\ge 2$ without imposing positivity constraints on the Hessian of the quadratic term, using translated Dirichlet problems, barrier constructions, and Perron’s method. The paper then translates the asymptotics into an initial-value problem to derive a polynomial convergence rate for viscosity solutions, and, under interior regularity (bounded Hessian), upgrades to exponential convergence via linearization and fundamental solutions. These results connect rigidity phenomena, asymptotic analysis, and the existence of viscosity solutions, offering a framework applicable to a broad range of dimensions and forcing terms.
Abstract
This paper investigates the asymptotic behavior at infinity of ancient solutions to the Lagrangian mean curvature flow. Under conditions that admit Liouville type rigidity theorems, we prove that every classical solution converges at infinity to the sum of a quadratic polynomial in $x$ and a linear function in $t$, with an explicitly derived exponential rate of convergence. As a critical part of the proof framework of this paper, we establish the existence of a global viscosity solution with prescribed asymptotic behavior at infinity, featuring two key innovations: (i) applicability to all dimensions $n\geq 2$, and (ii) no requirement that the Hessian matrix of the prescribed quadratic term be positive definite or close to a scalar multiple of the identity matrix. These results establish the relationship between Liouville type rigidity, asymptotic analysis at infinity, and the existence of viscosity solutions.
