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Related papers: On the fine structure of the free boundary for the…

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We study the regularity of the free boundary in the fully nonlinear thin obstacle problem. Our main result establishes that the free boundary is $C^1$ near regular points.

Analysis of PDEs · Mathematics 2016-03-31 Xavier Ros-Oton , Joaquim Serra

We start the investigation of free boundary variational models featuring varying singularities. The theory depends strongly on the nature of the singular power $\gamma(x)$ and how it changes. Under a mild continuity assumption on…

Analysis of PDEs · Mathematics 2025-11-12 Damião Araújo , Aelson Sobral , Eduardo V. Teixeira , José Miguel Urbano

We prove that a surface of prescribed mean curvature ($H$-surface) with free boundary on a two-dimensional $C^2$-manifold belongs to $C^{1,\frac{1}{2}}$ up to that the boundary, provided it is a-priori continuous. We allow the $H$-surface…

Analysis of PDEs · Mathematics 2020-08-31 Frank Müller

In this article we study solutions to the (interior) thin obstacle problem under low regularity assumptions on the coefficients, the obstacle and the underlying manifold. Combining the linearization method of Andersson \cite{An16} and the…

Analysis of PDEs · Mathematics 2016-10-26 Angkana Rüland , Wenhui Shi

The parabolic obstacle problem for the fractional Laplacian naturally arises in American option models when the assets prices are driven by pure jump L\'evy processes. In this paper we study the regularity of the free boundary. Our main…

Analysis of PDEs · Mathematics 2016-05-03 Begoña Barrios , Alessio Figalli , Xavier Ros-Oton

We obtain a generic regularity result for stationary integral $n$-varifolds with only strongly isolated singularities inside $N$-dimensional Riemannian manifolds, in absence of any restriction on the dimension ($n\geq 2$) and codimension.…

Differential Geometry · Mathematics 2025-03-03 Alessandro Carlotto , Yangyang Li , Zhihan Wang

We study the higher regularity of free boundaries in obstacle problems for integro-differential operators. Our main result establishes that, once free boundaries are $C^{1,\alpha}$, then they are $C^\infty$. This completes the study of…

Analysis of PDEs · Mathematics 2019-12-16 Nicola Abatangelo , Xavier Ros-Oton

We establish generic regularity results of free boundaries for solutions of the obstacle problem for the fractional Laplacian $(-\Delta)^s$. We prove that, for almost every obstacle, the free boundary contains only regular points up to…

Analysis of PDEs · Mathematics 2024-12-23 Matteo Carducci , Roberto Colombo

This paper deals with the obstacle problem for the infinity Laplacian. The main results are a characterization of the solution through comparison with cones that lie above the obstacle and the sharp $C^{1,1/3}$--regularity at the free…

Analysis of PDEs · Mathematics 2015-10-06 Julio D. Rossi , Eduardo V. Teixeira , José Miguel Urbano

In this paper, we analyze the singular shape of the free boundary at degenerate points in a three dimensional axisymmetric compressible gravity flow. For all possible degenerate points on the free surface, we prove that the only nontrivial…

Analysis of PDEs · Mathematics 2026-02-25 Lili Du , Chunlei Yang

We consider fully nonlinear obstacle-type problems of the form \begin{equation*} \begin{cases} F(D^{2}u,x)=f(x) & \text{a.e. in}B_{1}\cap\Omega,|D^{2}u|\le K & \text{a.e. in}B_{1}\backslash\Omega, \end{cases} \end{equation*} where $\Omega$…

Analysis of PDEs · Mathematics 2017-12-07 Emanuel Indrei , Andreas Minne

We study the regularity of the free boundary in the parabolic obstacle problem for the fractional Laplacian $(-\Delta)^s$ (and more general integro-differential operators) in the regime $s>\frac{1}{2}$. We prove that once the free boundary…

Analysis of PDEs · Mathematics 2022-07-27 Teo Kukuljan

We prove the -- to the best knowledge of the authors -- first result on the fine asymptotic behavior of the regular part of the free boundary of the obstacle problem close to singularities. The result is motivated by our recent partial…

Analysis of PDEs · Mathematics 2023-10-18 Simon Eberle , Henrik Shahgholian , Georg Sebastian Weiss

We study the obstacle problem for integro-differential operators of order $2s$, with $s\in (0,1)$. Our main result establishes that the free boundary is $C^{1,\gamma}$ and $u\in C^{1,s}$ near all regular points. Namely, we prove the…

Analysis of PDEs · Mathematics 2017-06-07 Luis Caffarelli , Xavier Ros-Oton , Joaquim Serra

In this paper, we prove the existence and uniqueness of $W^{2,p}$ ($n<p<\infty$) solutions of a double obstacle problem with $C^{1,1}$ obstacle functions. Moreover, we show the optimal regularity of the solution and the local $C^1$…

Analysis of PDEs · Mathematics 2022-10-14 Ki-ahm Lee , Jinwan Park

In this article we study for the first time the regularity of the free boundary in the one-phase free boundary problem driven by a general nonlocal operator. Our main results establish that the free boundary is $C^{1,\alpha}$ near regular…

Analysis of PDEs · Mathematics 2025-03-25 Xavier Ros-Oton , Marvin Weidner

We obtain sharp local $C^{1,\alpha}$ regularity of solutions for singular obstacle problems, Euler-Lagrange equation of which is given by $$ \Delta_p u=\gamma(u-\varphi)^{\gamma-1}\,\text{ in }\,\{u>\varphi\}, $$ for $0<\gamma<1$ and…

Analysis of PDEs · Mathematics 2022-10-19 Damião J. Araújo , Rafayel Teymurazyan , Vardan Voskanyan

In the previous work [Interfaces Free Bound., 19, 351--369, 2017], de Queiroz and Shahgholian established the optimal $C^{1,\log}_{\mathrm{loc}}$ regularity of solutions for the obstacle problem with singular logarithmic forcing term…

Analysis of PDEs · Mathematics 2026-04-30 Lili Du , Xu Tang , Yi Zhou

We study the regularity of the free boundary in the obstacle for the $p$-Laplacian, $\min\bigl\{-\Delta_p u,\,u-\varphi\bigr\}=0$ in $\Omega\subset\mathbb R^n$. Here, $\Delta_p u=\textrm{div}\bigl(|\nabla u|^{p-2}\nabla u\bigr)$, and…

Analysis of PDEs · Mathematics 2017-01-20 Alessio Figalli , Brian Krummel , Xavier Ros-Oton

We study the regularity and well-posedness of physical solutions to the supercooled Stefan problem. Assuming only that the initial temperature is integrable, we prove that the free boundary, known to have jump discontinuities as a function…

Analysis of PDEs · Mathematics 2026-04-08 Sebastian Munoz