Lane--Emden Systems with Singular Nonlinearities for the Fully Nonlinear Elliptic Operator
Karan Rathore, Mohan Mallick, Ram Baran Verma
TL;DR
This work extends Lane–Emden theory to a fully nonlinear, non-divergence elliptic framework by studying a singular two-component system $F(D^2u,Du,u,x)=u^{-p}v^{-q}$, $F(D^2v,Dv,v,x)=u^{-r}v^{-s}$ in a bounded domain with Dirichlet boundary conditions. The authors develop barrier constructions based on eigenfunctions and distance-to-boundary estimates, and apply a Schauder fixed-point argument in a carefully defined cone to obtain existence results under precise relations among the exponents $(p,q,r,s)$. They establish sharp nonexistence criteria via boundary behavior and integral tests, and prove regularity and partial uniqueness results in various parameter regimes. The findings significantly generalize Lane–Emden-type analyses to fully nonlinear operators, clarifying how singular nonlinearities interact with boundary geometry to govern solvability and regularity of positive viscosity solutions.
Abstract
Consider \[ \begin{cases} F(D^2 u,Du,u,x) = u^{-p}v^{-q},~\text{in}~Ω\\ F(D^2 v,Dv,v,x)=u^{-r}v^{-s},~~\text{in}~~Ω\\ u,v>0~~\text{in}~~Ω\\ u=v=0~\quad~\text{on}~~\partialΩ, \end{cases} \] where $Ω$ is an open connected subset of $\mathbb{R}^{N}$ and $p,s$ are two non-negative and $q,r$ are positive real numbers. This article discuses the conditions in terms of the relations among $p,q,r$ and $s$ which lead to existence, uniqueness and non-existence of positive solutions to the system. Furthermore, we also have studied some regularity properties of solution of the system. These results are inspired by the study of Lane-Emden system of equations as in \cite{busca2002liouville,ghergu2010lane}.
