A lower bound for the stability constant in the Caffarelli--Kohn--Nirenberg inequality
Abstract
We study the dependence on the dimension of stability constants for the Caffarelli--Kohn--Nirenberg inequalities, using the weighted energy distance to the manifold of optimizers. In the subcritical non-degenerate case, i.e., bFS(a)<b<a+1 with a<0 and a<b<a+1 with a≥0, we prove βa,b/d≤ cd,a,b ≤ (4(1+a−b))/(d+4(1+a−b)) with a positive constant depending only on the weights, uniformly over all admissible dimensions. The upper bound shows that this dimensional order is optimal. The critical case a=b>0 exhibits a different dimensional scale, min{βSob,4a}/25d2 ≤ cd,a,a≤16a/d2+Oa(d−3), where βSob>0 is a universal Sobolev stability constant. In the degenerate case on the Felli--Schneider curve, for fixed a<0, we prove βaFS/d3 ≤c̃d,a,bFS(a) ≤32|a|/d3+Oa(d−4), where c̃ is the quartic stability constant given in [Frank-Peteranderl, CV\&PDE, 2024] and βaFS>0 is independent of d. The three cases thus have optimal dimensional orders d−1, d−2, and d−3, respectively.
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BibTeX
@misc{li2026lower,
title = {{A lower bound for the stability constant in the Caffarelli--Kohn--Nirenberg inequality}},
author = {Houwang Li and Juncheng Wei},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.41474},
eprint = {2610.41474},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.41474},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A lower bound for the stability constant in the Caffarelli--Kohn--Nirenberg inequality
AU - Houwang Li
AU - Juncheng Wei
PY - 2026
DA - 2026/10/30
PB - arXiv
DO - 10.48550/arxiv.2610.41474
UR - https://arxiv.org/abs/2610.41474
AB - We study the dependence on the dimension of stability constants for the Caffarelli--Kohn--Nirenberg inequalities, using the weighted energy distance to the manifold of optimizers. In the subcritical non-degenerate case, i.e., b_FS(a)<b<a+1 with a<0 and a<b<a+1 with a≥0, we prove β_a,b/d≤ c_d,a,b ≤ (4(1+a−b))/(d+4(1+a−b)) with a positive constant depending only on the weights, uniformly over all admissible dimensions. The upper bound shows that this dimensional order is optimal. The critical case a=b>0 exhibits a different dimensional scale, min{β_Sob,4a}/25d^2 ≤ c_d,a,a≤16a/d^2+O_a(d^−3), where β_Sob>0 is a universal Sobolev stability constant. In the degenerate case on the Felli--Schneider curve, for fixed a<0, we prove β_a^FS/d^3 ≤c̃_d,a,b_FS(a) ≤32|a|/d^3+O_a(d^−4), where c̃ is the quartic stability constant given in [Frank-Peteranderl, CV\&PDE, 2024] and β_a^FS>0 is independent of d. The three cases thus have optimal dimensional orders d^−1, d^−2, and d^−3, respectively.
ER -