On a metric measure space (X,ϱ,μ), consider the weight functions
if ϱ(x,z₀) < 1,
if ϱ(x,z₀) ≥ 1,
if ϱ(x,z₀) < 1,
if ϱ(x,z₀) ≥ 1,
where z₀ is a given point of X, and let be an operator kernel satisfying
for all x,y ∈ X such that ϱ(x,y) < 1,
for all x,y ∈ X such that ϱ(x,y)≥ 1,
where 0 < a < min(d,D), and d and D are respectively the local and global volume growth rate of the space X. We determine conditions on a, α₀, α₁, β₀, β₁ ∈ ℝ for the Hardy-Littlewood-Sobolev operator...