2022/03/04 by Verbitsky, Igor E.
#42B37 #Analysis of PDEs (math.AP) #FOS: Mathematics #Primary 31B15 #Secondary 35J61
paper · doi:10.48550/arxiv.2203.02531
We give bilateral pointwise estimates for positive solutions u to the sublinear integral equation u = G(σuq) + f \textrmin Ω, for 0 < q < 1, where σ≥ 0 is a measurable function, or a Radon measure, f ≥ 0, and G is the integral operator associated with a positive kernel G on Ω×Ω. Our main results, which include the existence criteria and uniqueness of solutions, hold for quasi-metric, or quasi-metrically modifiable kernels G. As a consequence, we obtain bilateral estimates, along with the existence and uniqueness, for positive solutions u, possibly unbounded, to sublinear elliptic equations involving the fractional Laplacian, (-Δ)^\fracα2 u = σuq + μ \textrmin Ω, u=0 \textrmin Ωc, where 0