On general Caffarelli-Kohn-Nirenberg type inequalities involving non-doubling weights in the case of $p=1$
Toshio Horiuchi
TL;DR
This work extends Caffarelli-Kohn-Nirenberg type inequalities to the case p=1 with general, including non-doubling, weights by introducing the weight framework $W(\mathbb{R}_+)$, their monotone rearrangements ($\varphi_w$, $\psi_w$) and the derived $v_w$, $V_w^q$ functionals. A non-degenerate condition (NDC) on $K(r)=|w(r)/(rw'(r))|$ near the origin governs the validity of the inequalities, enabling a robust $n$-dimensional CKN-type inequality via radial reduction and a careful change of variables. The paper proves a 1D inequality with optimal constants, lifts it to higher dimensions under NDC, and characterizes both necessity (via vanishing or explode-at-origin weights) and insufficiency (when $K(r)\to0$) regimes. An appendix consolidates non-critical CKN-type inequalities and symmetry properties of the best constants. Overall, the results provide a unified framework for weighted CKN inequalities at p=1 with broad weight classes and explicit constant behavior.
Abstract
We study the Caffarelli-Kohn-Nirenberg type inequalities in the case of $p=1$ and generalize them adopting weight functions $w(|x|)$ on $R^n$ with $w(t)$ in ${W}(R_+)$. Here ${W}(R_+)$ is a general class of weight functions on $R_+$ including non-doubling weights like $e^{1/t}$ and $e^{-1/t}$.
