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Let $E\subset \mathbb{R}^{n+1}$, $n\ge 2$, be an Ahlfors-David regular set of dimension $n$. We show that the weak-$A_\infty$ property of harmonic measure, for the open set $\Omega:= \mathbb{R}^{n+1}\setminus E$, implies uniform…

Classical Analysis and ODEs · Mathematics 2018-10-10 Steve Hofmann , Phi Le , José María Martell , Kaj Nyström

We consider parabolic systems in divergence form with piecewise $C^{(s+\delta)/2,s+\delta}$ coefficients and data in a bounded domain consisting of a finite number of cylindrical subdomains with interfacial boundaries in $C^{s+1+\mu}$,…

Analysis of PDEs · Mathematics 2022-06-14 Hongjie Dong , Longjuan Xu

Let $\mu$ be a doubling measure in $\mathbb{R}^n$. We investigate quantitative relations between the rectifiability of $\mu$ and its distance to flat measures. More precisely, for $x$ in the support $\Sigma$ of $\mu$ and $r > 0$, we…

Classical Analysis and ODEs · Mathematics 2014-08-29 Jonas Azzam , Guy David , Tatiana Toro

We introduce new flatness coefficients, which we call $\iota$-numbers, for Ahlfors $k$-regular sets in metric spaces ($k\in \mathbb{N}$). Using these coefficients for $k=1$, we characterize uniform $1$-rectifiability in rather general…

Metric Geometry · Mathematics 2025-05-22 Katrin Fässler , Ivan Yuri Violo

We introduce a notion of admissible Hermitian metrics on parabolic bundles and define positivity properties for the same. We develop Chern-Weil theory for parabolic bundles and prove that our metric notions coincide with the already…

Differential Geometry · Mathematics 2018-10-15 Indranil Biswas , Vamsi Pritham Pingali

In this paper, we study parabolic equations in divergence form with coefficients that are singular degenerate as some Muckenhoupt weight functions in one spatial variable. Under certain conditions, weighted reverse H\"{o}lder's inequalities…

Analysis of PDEs · Mathematics 2018-11-16 Hongjie Dong , Tuoc Phan

We show that if a non-trivial measure in the plane admits, at almost every point, positive and finite $\alpha$-dimensional density with respect to some norm, then $\alpha$ must be an integer.

Classical Analysis and ODEs · Mathematics 2025-08-22 Giacomo Del Nin , Andrea Merlo

This work discusses parabolic Muckenhoupt weights on spaces of homogeneous type, i.e.\ quasi-metric spaces with both a doubling measure and an additional monotone geodesic property. The main results include a characterization in terms of…

Analysis of PDEs · Mathematics 2022-08-18 Juha Kinnunen , Kim Myyryläinen , Dachun Yang , Chenfeng Zhu

A simple proof is given for a generalized form of a theorem of Soshnikov. The latter states that the Janossy densities for multilevel determinantal ensembles supported on measurable subspaces of a set of measure spaces are constructed by…

Mathematical Physics · Physics 2009-01-22 J. Harnad

We establish a new regularity property for weak solutions of parabolic systems with coefficients depending measurably on time as well as on all spatial variables. Namely, weak solutions are locally H{\"o}lder continuous Lp valued functions…

Analysis of PDEs · Mathematics 2018-09-05 Pascal Auscher , Simon Bortz , Moritz Egert , Olli Saari

David and Semmes proved that if all CZOs (of suitable dimension) are bounded with respect to an Ahlfors regular measure, then the measure is uniformly rectifiable. We extend this theorem to the parabolic space and the first Heisenberg…

Analysis of PDEs · Mathematics 2026-01-27 John Hoffman , Ben Jaye

The Weil-Petersson and Takhtajan-Zograf metrics on the Riemann moduli spaces of complex structures for an $n$-fold punctured oriented surface of genus $g,$ in the stable range $g+2n>2,$ are shown here to have complete asymptotic expansions…

Differential Geometry · Mathematics 2018-06-01 Richard Melrose , Xuwen Zhu

Using variational methods, we prove local higher integrability for the minimal p-weak upper gradients of parabolic quasiminimizers in metric measure spaces. We assume the measure to be doubling and the underlying space to be such that a…

Analysis of PDEs · Mathematics 2013-01-18 Mathias Masson , Michele Miranda , Fabio Paronetto , Mikko Parviainen

We consider an inverse problem of reconstructing a degeneracy point in the diffusion coefficient in a one-dimensional parabolic equation by measuring the normal derivative on one side of the domain boundary. We analyze the sensitivity of…

Analysis of PDEs · Mathematics 2023-11-17 Piermarco Cannarsa , Anna Doubova , Masahiro Yamamoto

We demonstrate a measure theoretical approach to the local regularity of weak supersolutions to elliptic and parabolic equations in divergence form. In the first part, we show that weak supersolutions become lower semicontinuous after…

Analysis of PDEs · Mathematics 2021-01-20 Naian Liao

We provide very mild sufficient conditions for space-time domains (non-necessarily cylindrical) which ensure that the continuous Dirichlet problem and the H\"older Dirichlet problem are well-posed, for any parabolic operator in divergence…

Analysis of PDEs · Mathematics 2025-10-07 Pablo Hidalgo-Palencia , Cody Hutcheson , Joseph Kasel

We prove that in a complete metric space $X$, $1$-rectifiability of a set $E\subset X$ with $\mathcal{H}^1(E)<\infty$ and positive lower density $\mathcal{H}^1$-a.e. is implied by the property that all tangent spaces are connected metric…

Metric Geometry · Mathematics 2026-01-21 David Bate , Phoebe Valentine

We prove the $W^{1,2}_p$-estimate and solvability for the Dirichlet problem of second-order parabolic equations in simple convex polytopes with time irregular coefficients, when $p\in (1,2]$. We also consider the corresponding Neumann…

Analysis of PDEs · Mathematics 2014-07-28 Hongjie Dong , Doyoon Kim

We provide several equivalent characterizations of locally flat, $d$-Ahlfors regular, uniformly rectifiable sets $E$ in $\mathbb{R}^n$ with density close to $1$ for any dimension $d \in \mathbb{N}$ with $1 \le d \le n-1$. In particular, we…

Classical Analysis and ODEs · Mathematics 2024-02-29 Cole Jeznach

Global and local weighted Gagliardo-Nirenberg inequalities with doubling measures are established. These inequalities are key ingredients for the regularity theory and existence of strong solutions for strongly coupled parabolic and…

Functional Analysis · Mathematics 2016-12-30 Dung Le