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Bibliographic Details
Main Author: Tan, Jin
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2311.18407
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author Tan, Jin
author_facet Tan, Jin
contents We investigate the global-in-time existence and uniqueness of weak solutions for a family of equations introduced by Moffatt to model magnetic relaxation. These equations are topology-preserving and admit all stationary solutions to the classical incompressible Euler equations as steady states. In the work of Beekie, Friedlander and Vicol, global regularity results have been established for initial magnetic field B0 $\in$ Hs(Td)(s > d/2+1) when the regularization parameter $γ$ in the equations satisfies $γ$ > $γ$c := d/2+1. Global regularity for $γ$ $\in$ [0, $γ$c] is left as an open problem, as well as the existence of weak solutions with rough initial data for any $γ$ $\ge$ 0. In this paper, we show that for any solenoidal magnetic field B0 $\in$ L2(Td) there exists a unique global weak solution when $γ$ > $γ$c. Moreover, the solution can propagate higher-order Sobolev regularity. These results hold true for the borderline case $γ$ = $γ$c only if B0 $\in$ L2+(Td).
format Preprint
id arxiv_https___arxiv_org_abs_2311_18407
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Weak solutions of Moffatt's magnetic relaxation equations
Tan, Jin
Analysis of PDEs
We investigate the global-in-time existence and uniqueness of weak solutions for a family of equations introduced by Moffatt to model magnetic relaxation. These equations are topology-preserving and admit all stationary solutions to the classical incompressible Euler equations as steady states. In the work of Beekie, Friedlander and Vicol, global regularity results have been established for initial magnetic field B0 $\in$ Hs(Td)(s > d/2+1) when the regularization parameter $γ$ in the equations satisfies $γ$ > $γ$c := d/2+1. Global regularity for $γ$ $\in$ [0, $γ$c] is left as an open problem, as well as the existence of weak solutions with rough initial data for any $γ$ $\ge$ 0. In this paper, we show that for any solenoidal magnetic field B0 $\in$ L2(Td) there exists a unique global weak solution when $γ$ > $γ$c. Moreover, the solution can propagate higher-order Sobolev regularity. These results hold true for the borderline case $γ$ = $γ$c only if B0 $\in$ L2+(Td).
title Weak solutions of Moffatt's magnetic relaxation equations
topic Analysis of PDEs
url https://arxiv.org/abs/2311.18407