2025/09/10 by Beuvin, Nicolas, Farina, Alberto
#Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.2509.08431
We prove new one-dimensional symmetry results for non-negative solutions, possibly unbounded, to the semilinear equation -Δu= f(u) in the upper half-space ℝN+. Some Liouville-type theorems are also proven in the case of differential inequalities in ℝN+, even without imposing any boundary condition. Although subject to dimensional restrictions, our results apply to a broad family of functions f. In particular, they apply to all non-negative f that behaves at least linearly at infinity.