A paradifferential approach for well-posedness of the Muskat problem

HQ Nguyen, B Pausader - Archive for Rational Mechanics and Analysis, 2020 - Springer
We study the Muskat problem for one fluid or two fluids, with or without viscosity jump, with or
without rigid boundaries, and in arbitrary space dimension d of the interface. The Muskat …

Regularity of the free boundary for the two-phase Bernoulli problem

G De Philippis, L Spolaor, B Velichkov - Inventiones mathematicae, 2021 - Springer
We prove a regularity theorem for the free boundary of minimizers of the two-phase Bernoulli
problem, completing the analysis started by Alt, Caffarelli and Friedman in the 80s. As a …

Lyapunov functions, identities and the Cauchy problem for the Hele–Shaw equation

T Alazard, N Meunier, D Smets - Communications in Mathematical …, 2020 - Springer
This article is devoted to the study of the Hele–Shaw equation. We introduce an approach
inspired by the water-wave theory. Starting from a reduction to the boundary, introducing the …

Global well‐posedness for the one‐phase Muskat problem

H Dong, F Gancedo, HQ Nguyen - Communications on Pure …, 2023 - Wiley Online Library
The free boundary problem for a two‐dimensional fluid permeating a porous medium is
studied. This is known as the one‐phase Muskat problem and is mathematically equivalent …

Self-similar solutions for the Muskat equation

E García-Juárez, J Gómez-Serrano, HQ Nguyen… - Advances in …, 2022 - Elsevier
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The Hele-Shaw semi-flow

T Alazard, H Koch - arXiv preprint arXiv:2312.13678, 2023 - arxiv.org
We prove that the Cauchy problem is well-posed in a strong sense and in a general setting.
Our main result is the construction of an abstract semi-flow for the Hele-Shaw problem within …

Functional inequalities and strong Lyapunov functionals for free surface flows in fluid dynamics

T Alazard, D Bresch - Interfaces and Free Boundaries, 2023 - ems.press
This paper is motivated by the study of Lyapunov functionals for the Hele-Shaw and Mullins-
Sekerka equations describing free surface flows in fluid dynamics. We prove that the L2 …

Rectifiability and uniqueness of blow-ups for points with positive Alt–Caffarelli–Friedman limit

M Allen, D Kriventsov, R Neumayer - Mathematische Annalen, 2025 - Springer
We study the regularity of the interface between the disjoint supports of a pair of nonnegative
subharmonic functions. The portion of the interface where the Alt–Caffarelli–Friedman (ACF) …

Refined Rellich boundary inequalities for the derivatives of a harmonic function

S Agrawal, T Alazard - Proceedings of the American Mathematical Society, 2023 - ams.org
The classical Rellich inequalities imply that the $ L^ 2$-norms of the normal and tangential
derivatives of a harmonic function are equivalent. In this note, we prove several refined …

Convexity and the Hele–Shaw equation

T Alazard - Water Waves, 2021 - Springer
Walter Craig's seminal works on the water-wave problem established the importance of
several exact identities: Zakharov's hamiltonian formulation, shape derivative formula for the …