{"title":"Sharp ill-posedness for the Hunter–Saxton equation on the line","authors":"","doi":"10.1007/s00028-024-00962-x","DOIUrl":null,"url":null,"abstract":"<h3>Abstract</h3> <p>The purpose of this paper is to give an exact division for the well-posedness and ill-posedness (non-existence) of the Hunter–Saxton equation on the line. Since the force term is not bounded in the classical Besov spaces (even in the classical Sobolev spaces), a new mixed space <span> <span>\\(\\mathcal {B}\\)</span> </span> is constructed to overcome this difficulty. More precisely, if the initial data <span> <span>\\(u_0\\in \\mathcal {B}\\cap \\dot{H}^{1}(\\mathbb {R}),\\)</span> </span> the local well-posedness of the Cauchy problem for the Hunter–Saxton equation is established in this space. Contrariwise, if <span> <span>\\(u_0\\in \\mathcal {B}\\)</span> </span> but <span> <span>\\(u_0\\notin \\dot{H}^{1}(\\mathbb {R}),\\)</span> </span> the norm inflation and hence the ill-posedness is presented. It’s worth noting that this norm inflation occurs in the low frequency part, which exactly leads to a non-existence result. Moreover, the above result clarifies a corollary with physical significance such that all the smooth solutions in <span> <span>\\(L^{\\infty }(0,T;L^{\\infty }(\\mathbb {R}))\\)</span> </span> must have the <span> <span>\\(\\dot{H}^1\\)</span> </span> norm.</p>","PeriodicalId":51083,"journal":{"name":"Journal of Evolution Equations","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Evolution Equations","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00028-024-00962-x","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
The purpose of this paper is to give an exact division for the well-posedness and ill-posedness (non-existence) of the Hunter–Saxton equation on the line. Since the force term is not bounded in the classical Besov spaces (even in the classical Sobolev spaces), a new mixed space \(\mathcal {B}\) is constructed to overcome this difficulty. More precisely, if the initial data \(u_0\in \mathcal {B}\cap \dot{H}^{1}(\mathbb {R}),\) the local well-posedness of the Cauchy problem for the Hunter–Saxton equation is established in this space. Contrariwise, if \(u_0\in \mathcal {B}\) but \(u_0\notin \dot{H}^{1}(\mathbb {R}),\) the norm inflation and hence the ill-posedness is presented. It’s worth noting that this norm inflation occurs in the low frequency part, which exactly leads to a non-existence result. Moreover, the above result clarifies a corollary with physical significance such that all the smooth solutions in \(L^{\infty }(0,T;L^{\infty }(\mathbb {R}))\) must have the \(\dot{H}^1\) norm.
期刊介绍:
The Journal of Evolution Equations (JEE) publishes high-quality, peer-reviewed papers on equations dealing with time dependent systems and ranging from abstract theory to concrete applications.
Research articles should contain new and important results. Survey articles on recent developments are also considered as important contributions to the field.
Particular topics covered by the journal are:
Linear and Nonlinear Semigroups
Parabolic and Hyperbolic Partial Differential Equations
Reaction Diffusion Equations
Deterministic and Stochastic Control Systems
Transport and Population Equations
Volterra Equations
Delay Equations
Stochastic Processes and Dirichlet Forms
Maximal Regularity and Functional Calculi
Asymptotics and Qualitative Theory of Linear and Nonlinear Evolution Equations
Evolution Equations in Mathematical Physics
Elliptic Operators