Abstract This paper is devoted to quantitative refinements of the nonlocal Sobolev inequality with explicit determination of stability constants. In the single-bubble regime, we rigorously prove that the optimal stability constant c HLS = inf u ∈ D 1,2 ( R N ) \ M ‖ ∇ u ‖ L 2 ( R N ) 2 − S HLS ∫ R N I μ ∗ | u | 2 μ * | u | 2 μ * d x 1 2 μ *
Qian Zhang (Tue,) studied this question.