I give several results on stability of certain Khintchine-type
inequalities for Rademacher random variables and random vectors uniform
on Euclidean spheres. By stability we mean an inequality strengthened by
some positive deficit depending on distance from the extremizer. I will
discuss the results from the papers Stability of Khintchine
inequalities with optimal constants between the second and the $p$-th
moment for $p \ge 3$ (arXiv:2503.07001) and Khinchin inequalities for
uniforms on spheres with a deficit (arXiv:2506.22040), focusing mostly
on the second one.
The talk will be closely related to my previous talk given on March
20th, 2025, but there is no need to remember its content. Based on joint
work with Colin Tang and Tomasz Tkocz.