2025/04/28 by König, Tobias · 2 citations
#Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.2504.19939
We prove a stability inequality associated to the reverse Sobolev inequality on the sphere \mathbb Sn, for the full admissible parameter range s - (n)/(2) ∈ (0,1) ∪ (1,2). To implement the classical proof of Bianchi and Egnell, we overcome the main difficulty that the underlying operator A2s is not positive definite. As a consequence of our analysis and recent results from Gong et al. (arXiv:2503.20350 [math.AP]), the case s - (n)/(2) ∈ (1,2) remarkably constitutes the first example of a Sobolev-type stability inequality (i) whose best constant is explicit and (ii) which does not admit an optimizer.