{"title":"A Talenti comparison result for a class of Neumann boundary value problems","authors":"A. Celentano, C. Nitsch, C. Trombetti","doi":"10.1016/j.na.2025.113864","DOIUrl":"10.1016/j.na.2025.113864","url":null,"abstract":"<div><div>In this paper, we establish a comparison principle in terms of Lorentz norms and pointwise inequalities between a positive solution <span><math><mi>u</mi></math></span> to the Poisson equation with non-homogeneous Neumann boundary conditions and a specific positive solution <span><math><mi>v</mi></math></span> to the Schwarz symmetrized problem, which is related to <span><math><mi>u</mi></math></span> through an additional boundary condition.</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113864"},"PeriodicalIF":1.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On regularity of a kinetic boundary layer","authors":"Hongxu Chen","doi":"10.1016/j.na.2025.113891","DOIUrl":"10.1016/j.na.2025.113891","url":null,"abstract":"<div><div>We study the nonlinear steady Boltzmann equation in the half space, with phase transition and Dirichlet boundary condition. In particular, we study the regularity of the solution to the half-space problem in the situation that the gas is in contact with its condensed phase. We propose a novel kinetic weight and establish a weighted <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> estimate under the spatial domain <span><math><mrow><mi>x</mi><mo>∈</mo><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mi>∞</mi><mo>)</mo></mrow></mrow></math></span>, which is unbounded and not strictly convex. Additionally, we prove the <span><math><msup><mrow><mi>W</mi></mrow><mrow><mn>1</mn><mo>,</mo><mi>p</mi></mrow></msup></math></span> estimate without any weight for <span><math><mrow><mi>p</mi><mo><</mo><mn>2</mn></mrow></math></span>.</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113891"},"PeriodicalIF":1.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Uniqueness and multiple existence of positive radial solutions of the Brezis-Nirenberg problem on annular domains in S3","authors":"Naoki Shioji , Satoshi Tanaka , Kohtaro Watanabe","doi":"10.1016/j.na.2025.113886","DOIUrl":"10.1016/j.na.2025.113886","url":null,"abstract":"<div><div>The uniqueness and multiple existence of positive radial solutions to the Brezis-Nirenberg problem on a domain in the 3-dimensional unit sphere <span><math><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> <span><span><span><math><mfenced><mrow><mtable><mtr><mtd><msub><mrow><mi>Δ</mi></mrow><mrow><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></msub><mi>U</mi><mo>−</mo><mi>λ</mi><mi>U</mi><mo>+</mo><msup><mrow><mi>U</mi></mrow><mrow><mi>p</mi></mrow></msup></mtd><mtd><mo>=</mo><mn>0</mn><mo>,</mo><mspace></mspace><mi>U</mi><mo>></mo><mn>0</mn></mtd><mtd></mtd><mtd><mtext>in</mtext><msub><mrow><mi>Ω</mi></mrow><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></msub><mtext>,</mtext></mtd></mtr><mtr><mtd><mi>U</mi></mtd><mtd><mo>=</mo><mn>0</mn></mtd><mtd></mtd><mtd><mtext>on</mtext><mi>∂</mi><msub><mrow><mi>Ω</mi></mrow><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></msub><mtext>,</mtext></mtd></mtr></mtable></mrow></mfenced></math></span></span></span>for <span><math><mrow><mo>−</mo><msub><mrow><mi>λ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo><</mo><mi>λ</mi><mo>≤</mo><mn>1</mn></mrow></math></span> are shown, where <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></msub></math></span> is the Laplace–Beltrami operator, <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> is the first eigenvalue of <span><math><mrow><mo>−</mo><msub><mrow><mi>Δ</mi></mrow><mrow><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></msub></mrow></math></span> and <span><math><msub><mrow><mi>Ω</mi></mrow><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></msub></math></span> is an annular domain in <span><math><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span>: whose great circle distance (geodesic distance) from <span><math><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>)</mo></mrow></math></span> is greater than <span><math><msub><mrow><mi>θ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and less than <span><math><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>. A solution is said to be radial if it depends only on this geodesic distance. It is proved that the number of positive radial solutions of the problem changes with respect to the exponent <span><math><mi>p</mi></math></span> and parameter <span><math><mi>λ</mi></math></span> when <span><math><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mi>ɛ</mi></mrow></math></span>, <span><math><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></m","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113886"},"PeriodicalIF":1.3,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regularity for infinitely degenerate inhomogenous elliptic equations, Part I: The Moser Method","authors":"Lyudmila Korobenko , Cristian Rios , Eric Sawyer , Ruipeng Shen","doi":"10.1016/j.na.2025.113888","DOIUrl":"10.1016/j.na.2025.113888","url":null,"abstract":"<div><div>We show that if <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span> is equipped with a certain non-doubling metric and an Orlicz-Sobolev inequality holds for a special family of Young functions <span><math><mi>Φ</mi></math></span>, then weak solutions to quasilinear infinitely degenerate elliptic equations of the form <span><math><mrow><mo>−</mo><mi>div</mi><mi>A</mi><mfenced><mrow><mi>x</mi><mo>,</mo><mi>u</mi></mrow></mfenced><mo>∇</mo><mi>u</mi><mo>=</mo><msub><mrow><mi>ϕ</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>−</mo><msub><mrow><mi>div</mi></mrow><mrow><mi>A</mi></mrow></msub><msub><mrow><mover><mrow><mi>ϕ</mi></mrow><mo>→</mo></mover></mrow><mrow><mn>1</mn></mrow></msub></mrow></math></span> are locally bounded. This is obtained by the implementation of a Moser iteration method, what constitutes the first instance of such technique applied to infinite degenerate equations. The results presented here partially extend previously known estimates for solutions of similar equations in which the right hand side does not have a drift term. We also obtain bounds for small negative powers of nonnegative solutions, which will be applied in a subsequent paper to prove continuity of solutions. We also provide examples of geometries in which our abstract theorem is applicable. We consider the family of functions <span><math><mrow><msub><mrow><mi>f</mi></mrow><mrow><mi>k</mi><mo>,</mo><mi>σ</mi></mrow></msub><mfenced><mrow><mi>x</mi></mrow></mfenced><mo>=</mo><msup><mrow><mfenced><mrow><mi>x</mi></mrow></mfenced></mrow><mrow><msup><mrow><mfenced><mrow><msup><mrow><mo>ln</mo></mrow><mrow><mfenced><mrow><mi>k</mi></mrow></mfenced></mrow></msup><mfrac><mrow><mn>1</mn></mrow><mrow><mfenced><mrow><mi>x</mi></mrow></mfenced></mrow></mfrac></mrow></mfenced></mrow><mrow><mi>σ</mi></mrow></msup></mrow></msup><mo>,</mo><mspace></mspace><mspace></mspace><mspace></mspace><mi>k</mi><mo>∈</mo><mi>N</mi><mo>,</mo><mspace></mspace><mi>σ</mi><mo>></mo><mn>0</mn><mo>,</mo><mspace></mspace><mspace></mspace><mo>−</mo><mi>∞</mi><mo><</mo><mi>x</mi><mo><</mo><mi>∞</mi><mo>,</mo></mrow></math></span> infinitely degenerate at the origin, and show that all weak solutions to <span><math><mrow><mo>−</mo><mi>div</mi><mi>A</mi><mfenced><mrow><mi>x</mi><mo>,</mo><mi>y</mi><mo>,</mo><mi>u</mi></mrow></mfenced><mi>∇</mi><mi>u</mi><mo>=</mo><mi>ϕ</mi><mfenced><mrow><mi>x</mi><mo>,</mo><mi>y</mi></mrow></mfenced><mo>−</mo><msub><mrow><mi>div</mi></mrow><mrow><mi>A</mi></mrow></msub><msub><mrow><mover><mrow><mi>ϕ</mi></mrow><mo>→</mo></mover></mrow><mrow><mn>1</mn></mrow></msub><mfenced><mrow><mi>x</mi><mo>,</mo><mi>y</mi></mrow></mfenced><mo>,</mo><mspace></mspace><mspace></mspace><mspace></mspace><mi>A</mi><mfenced><mrow><mi>x</mi><mo>,</mo><mi>y</mi><mo>,</mo><mi>z</mi></mrow></mfenced><mo>∼</mo><mfenced><mrow><mtable><mtr><mtd><mn>1</mn></mtd><mtd><mn>0</mn></mtd></mtr><mtr><mtd><mn>0</mn></mtd><mtd><msub><mrow><mi>f</mi></mrow>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113888"},"PeriodicalIF":1.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Best constants for weighted Hardy inequalities in the exterior of balls and circular cylinders","authors":"Stathis Filippas, Achilles Tertikas","doi":"10.1016/j.na.2025.113885","DOIUrl":"10.1016/j.na.2025.113885","url":null,"abstract":"<div><div>We consider the weighted Hardy inequality <span><span><span><math><mrow><msub><mrow><mo>∫</mo></mrow><mrow><mi>Ω</mi></mrow></msub><mfrac><mrow><msup><mrow><mrow><mo>|</mo><mo>∇</mo><mi>u</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>|</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></mrow><mrow><msup><mrow><mi>d</mi></mrow><mrow><mi>s</mi><mo>−</mo><mn>2</mn></mrow></msup><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></mfrac><mspace></mspace><mi>d</mi><mi>x</mi><mo>≥</mo><msub><mrow><mi>c</mi></mrow><mrow><mi>s</mi></mrow></msub><mrow><mo>(</mo><mi>Ω</mi><mo>)</mo></mrow><msub><mrow><mo>∫</mo></mrow><mrow><mi>Ω</mi></mrow></msub><mfrac><mrow><msup><mrow><mi>u</mi></mrow><mrow><mn>2</mn></mrow></msup><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow><mrow><msup><mrow><mi>d</mi></mrow><mrow><mi>s</mi></mrow></msup><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></mfrac><mspace></mspace><mi>d</mi><mi>x</mi><mo>,</mo><mspace></mspace><mspace></mspace><mspace></mspace><mspace></mspace><mspace></mspace><mspace></mspace><mo>∀</mo><mi>u</mi><mo>∈</mo><msubsup><mrow><mi>C</mi></mrow><mrow><mi>c</mi></mrow><mrow><mi>∞</mi></mrow></msubsup><mrow><mo>(</mo><mi>Ω</mi><mo>)</mo></mrow><mo>.</mo></mrow></math></span></span></span>For <span><math><mrow><mi>s</mi><mo>></mo><mn>1</mn></mrow></math></span>, <span><math><mrow><mi>n</mi><mo>≥</mo><mn>2</mn></mrow></math></span>, <span><math><mrow><mi>s</mi><mo>≠</mo><mi>n</mi></mrow></math></span> we compute the best constant in the case where <span><math><mi>Ω</mi></math></span> is either the complement of a ball or the complement of a circular cylinder. Typically one is able to compute best constants if the domain is weakly mean convex. In our case the domains are not weakly mean convex. The best constant depends on the parameter <span><math><mi>s</mi></math></span> in a surprising way. For instance when <span><math><mrow><mi>n</mi><mo>></mo><mn>3</mn></mrow></math></span> then <span><span><span><math><mrow><msub><mrow><mi>c</mi></mrow><mrow><mi>s</mi></mrow></msub><mrow><mo>(</mo><mi>Ω</mi><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><mrow><mo>(</mo><mi>n</mi><mo>−</mo><mn>2</mn><mo>)</mo></mrow><mrow><mo>(</mo><mi>n</mi><mo>−</mo><mi>s</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow><mrow><mo>(</mo><mi>s</mi><mo>−</mo><mn>2</mn><mo>)</mo></mrow></mrow><mrow><msup><mrow><mrow><mo>(</mo><mi>n</mi><mo>−</mo><mn>3</mn><mo>)</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mo>,</mo><mspace></mspace><mspace></mspace><mtext>if</mtext><mspace></mspace><mspace></mspace><mfrac><mrow><mn>3</mn><mi>n</mi><mo>−</mo><mn>5</mn></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></mfrac><mo><</mo><mi>s</mi><mo><</mo><mfrac><mrow><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mn>3</mn><mi>n</mi><mo>+</mo><mn>4</mn></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></mfrac><mo>,</mo></mrow></math></span></span></span>whereas <span><span><span><math><mrow><msub><mrow><mi>c</m","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113885"},"PeriodicalIF":1.3,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144481759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Kato square root problem for parabolic operators with an anti-symmetric part in BMO","authors":"Alireza Ataei, Kaj Nyström","doi":"10.1016/j.na.2025.113876","DOIUrl":"10.1016/j.na.2025.113876","url":null,"abstract":"<div><div>We solve the Kato square root problem for parabolic operators whose coefficients can be written as the sum of a complex part, which is coercive, and a real anti-symmetric part, which is in <span><math><mtext>BMO</mtext></math></span>. In particular, we allow for certain unbounded coefficients.</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113876"},"PeriodicalIF":1.3,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Long-time asymptotics for the physical vacuum free boundary problem of compressible Euler equations with time-dependent damping","authors":"Yan-Lin Wang","doi":"10.1016/j.na.2025.113887","DOIUrl":"10.1016/j.na.2025.113887","url":null,"abstract":"<div><div>The global existence theory and long-time asymptotics of smooth solution for the physical vacuum free boundary problem of the one-dimensional compressible Euler equations with time-dependent damping <span><math><mrow><mo>−</mo><mi>μ</mi><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>+</mo><mi>t</mi><mo>)</mo></mrow></mrow><mrow><mo>−</mo><mi>λ</mi></mrow></msup><mi>ρ</mi><mi>u</mi></mrow></math></span> have been studied in this paper. The role of <span><math><mi>μ</mi></math></span> has been well investigated in this paper. If <span><math><mi>μ</mi></math></span> is larger than a positive constant <span><math><mrow><mi>μ</mi><mrow><mo>(</mo><mi>λ</mi><mo>,</mo><mi>γ</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mrow></math></span> depending on <span><math><mrow><mi>λ</mi><mo>∈</mo><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></mrow></mrow></math></span> and adiabatic exponent <span><math><mrow><mi>γ</mi><mo>></mo><mn>1</mn></mrow></math></span>, then we obtain the global existence theory for Euler equations with time-dependent damping by a new approach, which has improved the decay rates of smooth solutions obtained in Pan’s work (Pan 2021). The strategy for the construction of time weight in this paper is believed to extend to the problem of three-dimensional model in spherical symmetry, similarly.</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113887"},"PeriodicalIF":1.3,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimal Lp-approximation of convex sets by convex subsets","authors":"Zakaria Fattah , Ilias Ftouhi , Enrique Zuazua","doi":"10.1016/j.na.2025.113866","DOIUrl":"10.1016/j.na.2025.113866","url":null,"abstract":"<div><div>Given a convex set <span><math><mi>Ω</mi></math></span> of <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span>, we consider the shape optimization problem of finding a convex subset <span><math><mrow><mi>ω</mi><mo>⊂</mo><mi>Ω</mi></mrow></math></span>, of a given measure, minimizing the <span><math><mi>p</mi></math></span>-distance functional <span><math><mrow><msub><mrow><mi>J</mi></mrow><mrow><mi>p</mi></mrow></msub><mrow><mo>(</mo><mi>ω</mi><mo>)</mo></mrow><mo>≔</mo><msup><mrow><mfenced><mrow><msub><mrow><mo>∫</mo></mrow><mrow><msup><mrow><mi>S</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup></mrow></msub><msup><mrow><mrow><mo>|</mo><msub><mrow><mi>h</mi></mrow><mrow><mi>Ω</mi></mrow></msub><mo>−</mo><msub><mrow><mi>h</mi></mrow><mrow><mi>ω</mi></mrow></msub><mo>|</mo></mrow></mrow><mrow><mi>p</mi></mrow></msup><mi>d</mi><msup><mrow><mi>H</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow></msup></mrow></mfenced></mrow><mrow><mfrac><mrow><mn>1</mn></mrow><mrow><mi>p</mi></mrow></mfrac></mrow></msup><mo>,</mo></mrow></math></span> where <span><math><mrow><mn>1</mn><mo>≤</mo><mi>p</mi><mo><</mo><mi>∞</mi></mrow></math></span> and <span><math><msub><mrow><mi>h</mi></mrow><mrow><mi>ω</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>h</mi></mrow><mrow><mi>Ω</mi></mrow></msub></math></span> are the support functions of <span><math><mi>ω</mi></math></span> and the fixed container <span><math><mi>Ω</mi></math></span>, respectively.</div><div>We prove the existence of solutions and show that this minimization problem <span><math><mi>Γ</mi></math></span>-converges, when <span><math><mi>p</mi></math></span> tends to <span><math><mrow><mo>+</mo><mi>∞</mi></mrow></math></span>, towards the problem of finding a convex subset <span><math><mrow><mi>ω</mi><mo>⊂</mo><mi>Ω</mi></mrow></math></span>, of a given measure, minimizing the Hausdorff distance to the convex <span><math><mi>Ω</mi></math></span>.</div><div>In the planar case, we show that the free parts of the boundary of the optimal shapes, i.e., those that are in the interior of <span><math><mi>Ω</mi></math></span>, are given by polygonal lines.</div><div>Still in the 2D setting, from a computational perspective, the classical method based on optimizing Fourier coefficients of support functions is not efficient, as it is unable to efficiently capture the presence of segments on the boundary of optimal shapes. We subsequently propose a method combining Fourier analysis and a numerical scheme recently introduced in Bogosel (2023), allowing to obtain accurate results, as demonstrated through numerical experiments.</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113866"},"PeriodicalIF":1.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On a global integral equation arising in the discretization of granular flows","authors":"Adrian Tudorascu","doi":"10.1016/j.na.2025.113871","DOIUrl":"10.1016/j.na.2025.113871","url":null,"abstract":"<div><div>We construct approximations to the solution for the homogeneous nonlinear friction equation with generic initial data by time-discretizing the fow in the Wasserstein space.The associated Euler-Lagrange equation for the optimal map is a global integral equation which we analyze in detail. It is remarkable that the solution is explicit up to its <span><math><msup><mrow><mi>L</mi></mrow><mn>2</mn></msup></math></span> -norm. An estimate of the long time behavior of the support of the solution to the original PDE arises as a consequence</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113871"},"PeriodicalIF":1.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stability of stationary solutions in the inflow problem for full quantum hydrodynamic equations","authors":"Chol Hong , Hakho Hong , Yong-Hyok Jo","doi":"10.1016/j.na.2025.113842","DOIUrl":"10.1016/j.na.2025.113842","url":null,"abstract":"<div><div>In this paper, we are concerned with the inflow problem in the half line <span><math><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mi>∞</mi><mo>)</mo></mrow></math></span> to the full hydrodynamic equations with quantum effects. We first give some necessary and sufficient conditions for the existence of the stationary solutions with the aid of center manifold theory. We also show the stability of the stationary solutions under smallness assumptions on the initial perturbation in the Sobolev space. The analysis is based on the elementary <span><math><mrow><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo></mrow></math></span>energy method, but various techniques are introduced to establish the uniform energy estimates.</div></div>","PeriodicalId":49749,"journal":{"name":"Nonlinear Analysis-Theory Methods & Applications","volume":"261 ","pages":"Article 113842"},"PeriodicalIF":1.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}