{"title":"Contact discontinuities for 2-D isentropic Euler are unique in 1-D but wildly non-unique otherwise","authors":"Sam G. Krupa, László Székelyhidi Jr","doi":"arxiv-2409.11296","DOIUrl":"https://doi.org/arxiv-2409.11296","url":null,"abstract":"We develop a general framework for studying non-uniqueness of the Riemann\u0000problem for the isentropic compressible Euler system in two spatial dimensions,\u0000and in this paper we present the most delicate result of our method:\u0000non-uniqueness of the contact discontinuity. Our approach is computational, and\u0000uses the pressure law as an additional degree of freedom. The stability of the contact discontinuities for this system is a major open\u0000problem (see Gui-Qiang Chen and Ya-Guang Wang [Nonlinear partial differential\u0000equations, volume 7 of Abel Symposia. Springer, Heidelberg, 2012.]). We find a smooth pressure law $p$, verifying the physically relevant\u0000condition $p'>0$, such that for the isentropic compressible Euler system with\u0000this pressure law, contact discontinuity initial data is wildly non-unique in\u0000the class of bounded, admissible weak solutions. This result resolves the\u0000question of uniqueness for contact discontinuity solutions in the compressible\u0000regime. Moreover, in the same regularity class in which we have non-uniqueness of the\u0000contact discontinuity, i.e. $L^infty$, with no $BV$ regularity or\u0000self-similarity, we show that the classical contact discontinuity solution to\u0000the two-dimensional isentropic compressible Euler system is in fact unique in\u0000the class of bounded, admissible weak solutions if we restrict to 1-D\u0000solutions.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A limiting case of a theorem of C. Miranda for layer potentials in Schauder spaces","authors":"Massimo Lanza de Cristoforis","doi":"arxiv-2409.11132","DOIUrl":"https://doi.org/arxiv-2409.11132","url":null,"abstract":"The aim of this paper is to prove a theorem of C.~Miranda for the single and\u0000double layer potential corresponding to the fundamental solution of a second\u0000order differential operator with constant coefficients in Schauder spaces in\u0000the limiting case in which the open set is of class $C^{m,1}$ and the densities\u0000are of class $C^{m-1,1}$ for the single layer potential and of class $C^{m,1}$\u0000for the double layer potential for some nonzero natural number $m$. The\u0000treatment of the limiting case requires generalized Schauder spaces.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Global solutions to 3D quadratic nonlinear Schrödinger-type equation","authors":"Zihua Guo, Naijia Liu, Liang Song","doi":"arxiv-2409.10804","DOIUrl":"https://doi.org/arxiv-2409.10804","url":null,"abstract":"We consider the Cauchy problem to the 3D fractional Schr\"odinger equation\u0000with quadratic interaction of $ubar u$ type. We prove the global existence of\u0000solutions and scattering properties for small initial data. For the proof, one\u0000novelty is that we combine the normal form methods and the space-time resonance\u0000methods. Using the normal form transform enables us more flexibilities in\u0000designing the resolution spaces so that we can control various interactions. It\u0000is also convenient for the final data problem.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A note on the radially symmetry in the moving plane method","authors":"Shu-Yu Hsu","doi":"arxiv-2409.10834","DOIUrl":"https://doi.org/arxiv-2409.10834","url":null,"abstract":"Let $Omegasubsetmathbb{R}^n$, $nge 2$, be a bounded connected $C^2$\u0000domain. For any unit vector $nuinmathbb{R}^n$, let\u0000$T_{lambda}^{nu}={xinmathbb{R}^n:xcdotnu=lambda}$,\u0000$Sigma_{lambda}^{nu}={xinOmega:xcdotnu<lambda}$ and\u0000$x^{ast}=x-2(xcdotnu-lambda)nu$ be the reflection of a point\u0000$xinmathbb{R}^n$ about the plane $T_{lambda}^{nu}$. Let\u0000$widetilde{Sigma}_{lambda}^{nu}={xinOmega:x^{ast}inSigma_{lambda}^{nu}}$\u0000and $uin C^2(overline{Omega})$. Suppose for any unit vector\u0000$nuinmathbb{R}^n$, there exists a constant $lambda_{nu}inmathbb{R}$ such\u0000that $Omega$ is symmetric about the plane $T_{lambda_{nu}}^{nu}$ and $u$ is\u0000symmetric about the plane $T_{lambda_{nu}}^{nu}$ and satisfies\u0000(i)$,frac{partial u}{partialnu}(x)>0quadforall xin\u0000Sigma_{lambda_{nu}}^{nu}$ and (ii)$,frac{partial\u0000u}{partialnu}(x)<0quadforall xin\u0000widetilde{Sigma}_{lambda_{nu}}^{nu}$. We will give a simple proof that $u$\u0000is radially symmetric about some point $x_0inOmega$ and $Omega$ is a ball\u0000with center at $x_0$. Similar result holds for the domain $mathbb{R}^n$ and\u0000function $uin C^2(mathbb{R}^n)$ satisfying similar monotonicity and symmetry\u0000conditions. We also extend this result under weaker hypothesis on the function\u0000$u$.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Existence of an extremal function of Sobolev critical embedding with an $α$-homogeneous weight","authors":"Petr Gurka, Daniel Hauer","doi":"arxiv-2409.11193","DOIUrl":"https://doi.org/arxiv-2409.11193","url":null,"abstract":"In our previous publication [{em Calc. Var. Partial Differential Equations},\u000060(1):Paper No. 16, 27, 2021], we delved into examining a critical Sobolev-type\u0000embedding of a Sobolev weighted space into an exponential weighted Orlicz\u0000space. We specifically determined the optimal Moser-type constant for this\u0000embedding, utilizing the monomial weight introduced by Cabr'e and Ros-Oton\u0000[{em J. Differential Equations}, 255(11):4312--4336, 2013]. Towards the\u0000conclusion of that paper, we pledged to explore the existence of an extremal\u0000function within this framework. In this current work, we not only provide a positive affirmation to this\u0000inquiry but extend it to a broader range of weights known as\u0000emph{$alpha$-homogeneous weights}.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shivprasad KathaneIndian Institute of Technology Bombay Mumbai India, Shyamprasad KaragaddeIndian Institute of Technology Bombay Mumbai India
{"title":"A Physics Informed Neural Network (PINN) Methodology for Coupled Moving Boundary PDEs","authors":"Shivprasad KathaneIndian Institute of Technology Bombay Mumbai India, Shyamprasad KaragaddeIndian Institute of Technology Bombay Mumbai India","doi":"arxiv-2409.10910","DOIUrl":"https://doi.org/arxiv-2409.10910","url":null,"abstract":"Physics-Informed Neural Network (PINN) is a novel multi-task learning\u0000framework useful for solving physical problems modeled using differential\u0000equations (DEs) by integrating the knowledge of physics and known constraints\u0000into the components of deep learning. A large class of physical problems in\u0000materials science and mechanics involve moving boundaries, where interface flux\u0000balance conditions are to be satisfied while solving DEs. Examples of such\u0000systems include free surface flows, shock propagation, solidification of pure\u0000and alloy systems etc. While recent research works have explored applicability\u0000of PINNs for an uncoupled system (such as solidification of pure system), the\u0000present work reports a PINN-based approach to solve coupled systems involving\u0000multiple governing parameters (energy and species, along with multiple\u0000interface balance equations). This methodology employs an architecture\u0000consisting of a separate network for each variable with a separate treatment of\u0000each phase, a training strategy which alternates between temporal learning and\u0000adaptive loss weighting, and a scheme which progressively reduces the\u0000optimisation space. While solving the benchmark problem of binary alloy\u0000solidification, it is distinctly successful at capturing the complex\u0000composition profile, which has a characteristic discontinuity at the interface\u0000and the resulting predictions align well with the analytical solutions. The\u0000procedure can be generalised for solving other transient multiphysics problems\u0000especially in the low-data regime and in cases where measurements can reveal\u0000new physics.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Existence of multiple radial solutions for nonlinear equation involving the mean curvature operator in Lorentz-Minkowski space","authors":"Vittorio Coti Zelati, Xu Dong, Yuanhong Wei","doi":"arxiv-2409.11039","DOIUrl":"https://doi.org/arxiv-2409.11039","url":null,"abstract":"We prove existence of multiple radial solutions to the Dirichlet problem for\u0000nonlinear equations involving the mean curvature operator in Lorentz-Minkowski\u0000space and a nonlinear term of concave-convex type. Solutions are found using\u0000Szulkin's critical point theory for non-smooth functional. Multiplicity results\u0000are also given for some cases in which the nonlinearity depends also on the\u0000gradient of the solution.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Output-feedback stabilization of an underactuated network of N interconnected n + m hyperbolic PDE systems","authors":"Jean AuriolL2S","doi":"arxiv-2409.10087","DOIUrl":"https://doi.org/arxiv-2409.10087","url":null,"abstract":"In this article, we detail the design of an output feedback stabilizing\u0000control law for an underactuated network of N subsystems of n + m\u0000heterodirectional linear first-order hyperbolic Partial Differential Equations\u0000interconnected through their boundaries. The network has a chain structure, as\u0000only one of the subsystems is actuated. The available measurements are located\u0000at the opposite extremity of the chain. The proposed approach introduces a new\u0000type of integral transformation to tackle in-domain couplings in the different\u0000subsystems while guaranteeing a ''clear actuation path'' between the control\u0000input and the different subsystems. Then, it is possible to state several\u0000essential properties of each subsystem: output trajectory tracking,\u0000input-to-state stability, and predictability (the possibility of designing a\u0000state prediction). We recursively design a stabilizing state-feedback\u0000controller by combining these properties. We then design a state-observer that\u0000reconstructs delayed values of the states. This observer is combined with the\u0000state-feedback control law to obtain an output-feedback controller. Simulations\u0000complete the presentation.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Scattering for the generalized Hartree equation with a potential","authors":"Carlos M. Guzmán, Cristian Loli, Luis P. Yapu","doi":"arxiv-2409.10769","DOIUrl":"https://doi.org/arxiv-2409.10769","url":null,"abstract":"We consider the focusing generalized Hartree equation in $H^1(R^3)$ with a\u0000potential, begin{equation*} iu_t + Delta u - V(x)u + (I_gamma ast |u|^p\u0000)|u|^{p-2} u=0, end{equation*} where $I_gamma = frac{1}{|x|^{3-gamma}}$, $p\u0000geq 2$ and $gamma < 3$. In this paper, we prove scattering for the\u0000generalized Hartree equation with a potential in the intercritical case\u0000assuming radial initial data. The novelty of our approach lies in the use of a\u0000general mass-potential condition, incorporating the potential V, which extends\u0000the standard mass-energy framework. To this end, we employ a simplified method\u0000inspired by Dodson and Murphy cite{Dod-Mur}, based on Tao's scattering\u0000criteria and Morawetz estimates. This approach provides a more straightforward\u0000proof of scattering compared to the traditional\u0000concentration-compactness/rigidity method of Kenig and Merle cite{KENIG}.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Continuity of the linearized forward map of electrical impedance tomography from square-integrable perturbations to Hilbert-Schmidt operators","authors":"Joanna Bisch, Markus Hirvensalo, Nuutti Hyvönen","doi":"arxiv-2409.10671","DOIUrl":"https://doi.org/arxiv-2409.10671","url":null,"abstract":"This work considers the Fr'echet derivative of the idealized forward map of\u0000two-dimensional electrical impedance tomography, i.e., the linear operator that\u0000maps a perturbation of the coefficient in the conductivity equation over a\u0000bounded two-dimensional domain to the linear approximation of the corresponding\u0000change in the Neumann-to-Dirichlet boundary map. It is proved that the\u0000Fr'echet derivative is bounded from the space of square-integrable\u0000conductivity perturbations to the space of Hilbert--Schmidt operators on the\u0000mean-free $L^2$ functions on the domain boundary, if the background\u0000conductivity coefficient is constant and the considered simply-connected domain\u0000has a $C^{1,alpha}$ boundary. This result provides a theoretical framework for\u0000analyzing linearization-based one-step reconstruction algorithms of electrical\u0000impedance tomography in an infinite-dimensional setting.","PeriodicalId":501165,"journal":{"name":"arXiv - MATH - Analysis of PDEs","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}