Layer potentials for elliptic operators with DMO-type coefficients: big pieces $Tb$ theorem, quantitative rectifiability, and free boundary problems

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Merlo, Andrea, Mourgoglou, Mihalis, Puliatti, Carmelo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915312624992256
author Merlo, Andrea
Mourgoglou, Mihalis
Puliatti, Carmelo
author_facet Merlo, Andrea
Mourgoglou, Mihalis
Puliatti, Carmelo
contents For $n \geq 2$, we consider the operator $L_A = -\mathrm{div }(A(\cdot)\nabla)$, where $A$ is a uniformly elliptic $(n+1)\times(n+1)$ matrix with variable coefficients, a Radon measure $μ$ on $\mathbb{R}^{n+1}$, and the associated gradient of the single layer potential operator $T_μ$. Under a Dini-type assumption on the mean oscillation of the matrix $A$, we establish the following results: 1) A rectifiability criterion for $μ$ in terms of $T_μ$. Under quantitative geometric and analytic assumptions within a ball $B$ -- including an upper $n$-growth condition on $μ$ in $B$, a thin boundary condition, a scale-invariant decay condition expressed via a weighted sum of densities over dyadic dilations of $B$, and $L^2$ boundedness of the gradient of $T_μ$ -- we show the following: if the support of $μ$ lies very close to an $n$-plane in $B$, and $T_μ1$ is nearly constant on $B$ in the $L^2$ sense, then there exists a uniformly $n$-rectifiable set $Γ$ such that $μ(B \cap Γ) \gtrsim μ(B)$. 2) A $Tb$ theorem for suppressed $T_μ$, which extends a well-known theorem of Nazarov, Treil, and Volberg, and holds also for a broader class of singular integral operators. These results make it possible to prove both qualitative and quantitative one- and two-phase free boundary problems for elliptic measure, formulated in terms of (uniform) rectifiability, in bounded Wiener-regular domains.
format Preprint
id arxiv_https___arxiv_org_abs_2505_23478
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Layer potentials for elliptic operators with DMO-type coefficients: big pieces $Tb$ theorem, quantitative rectifiability, and free boundary problems
Merlo, Andrea
Mourgoglou, Mihalis
Puliatti, Carmelo
Analysis of PDEs
Classical Analysis and ODEs
42B37, 42B20, 35J15, 28A75, 28A75, 33C55
For $n \geq 2$, we consider the operator $L_A = -\mathrm{div }(A(\cdot)\nabla)$, where $A$ is a uniformly elliptic $(n+1)\times(n+1)$ matrix with variable coefficients, a Radon measure $μ$ on $\mathbb{R}^{n+1}$, and the associated gradient of the single layer potential operator $T_μ$. Under a Dini-type assumption on the mean oscillation of the matrix $A$, we establish the following results: 1) A rectifiability criterion for $μ$ in terms of $T_μ$. Under quantitative geometric and analytic assumptions within a ball $B$ -- including an upper $n$-growth condition on $μ$ in $B$, a thin boundary condition, a scale-invariant decay condition expressed via a weighted sum of densities over dyadic dilations of $B$, and $L^2$ boundedness of the gradient of $T_μ$ -- we show the following: if the support of $μ$ lies very close to an $n$-plane in $B$, and $T_μ1$ is nearly constant on $B$ in the $L^2$ sense, then there exists a uniformly $n$-rectifiable set $Γ$ such that $μ(B \cap Γ) \gtrsim μ(B)$. 2) A $Tb$ theorem for suppressed $T_μ$, which extends a well-known theorem of Nazarov, Treil, and Volberg, and holds also for a broader class of singular integral operators. These results make it possible to prove both qualitative and quantitative one- and two-phase free boundary problems for elliptic measure, formulated in terms of (uniform) rectifiability, in bounded Wiener-regular domains.
title Layer potentials for elliptic operators with DMO-type coefficients: big pieces $Tb$ theorem, quantitative rectifiability, and free boundary problems
topic Analysis of PDEs
Classical Analysis and ODEs
42B37, 42B20, 35J15, 28A75, 28A75, 33C55
url https://arxiv.org/abs/2505.23478