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Related papers: Differences between Robin and Neumann eigenvalues

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We consider the Laplacian on a metric graph, equipped with Robin ($\delta$-type) vertex condition at some of the graph vertices and Neumann-Kirchhoff condition at all others. The corresponding eigenvalues are called Robin eigenvalues,…

Mathematical Physics · Physics 2024-03-21 Ram Band , Holger Schanz , Gilad Sofer

We prove an existence result for Robin boundary value problems modeled on \[ \begin{cases} \Delta u + |\nabla u|^2 + \lambda f(x) = 0 & \text{in } \Omega \\ \frac{\partial u}{\partial \nu} + \beta u = 0 & \text{on } \partial\Omega…

Analysis of PDEs · Mathematics 2025-12-24 Francesco Della Pietra , Giuseppina di Blasio , Giuseppe Riey

We consider the first eigenvalue $\lambda_1(\Omega,\sigma)$ of the Laplacian with Robin boundary conditions on a compact Riemannian manifold $\Omega$ with smooth boundary, $\sigma\in\bf R$ being the Robin boundary parameter. When $\sigma>0$…

Analysis of PDEs · Mathematics 2019-04-17 Alessandro Savo

Let $\Omega\subset\mathbb{R}^N$, $N\ge 2,$ be a bounded domain with an outward power-like peak which is assumed not too sharp in a suitable sense. We consider the Laplacian $u\mapsto -\Delta u$ in $\Omega$ with the Robin boundary condition…

Analysis of PDEs · Mathematics 2020-06-23 Hynek Kovarik , Konstantin Pankrashkin

Let $\Omega\subset \RR^2$ be a domain having a compact boundary $\Sigma$ which is Lipschitz and piecewise $C^4$ smooth, and let $\nu$ denote the inward unit normal vector on $\Sigma$. We study the principal eigenvalue $E(\beta)$ of the…

Spectral Theory · Mathematics 2013-09-04 Konstantin Pankrashkin

Comparing Neumann and Dirichlet eigenvalues of the Laplacian on a bounded domain $\Omega\subseteq\Rbb^n$ is a topic that goes back at least to the work of P\'olya \cite{polya}. We study the effect of the isoperimetric ratio of $\Omega$ on…

Spectral Theory · Mathematics 2025-04-28 Lawford Hatcher

This paper deals with the Neumann eigenvalue problem for the Hermite operator defined in a convex, possibly unbounded, planar domain $\Omega$, having one axis of symmetry passing through the origin. We prove a sharp lower bound for the…

Analysis of PDEs · Mathematics 2012-09-28 B. Brandolini , F. Chiacchio , C. Trombetti

In this note, we investigate upper bounds of the Neumann eigenvalue problem for the Laplacian of a bounded domain (with smooth boundary) in a given complete (not compact a priori) Riemannian manifold with Ricci bounded below . For this, we…

Differential Geometry · Mathematics 2008-02-21 Bruno Colbois , Daniel Maerten

For every given $\beta<0$, we study the problem of maximizing the first Robin eigenvalue of the Laplacian $\lambda_\beta(\Omega)$ among convex (not necessarily smooth) sets $\Omega\subset\mathbb{S}^{n}$ with fixed perimeter. In particular,…

Analysis of PDEs · Mathematics 2025-07-30 Paolo Acampora , Antonio Celentano , Emanuele Cristoforoni , Carlo Nitsch , Cristina Trombetti

The second eigenvalue of the Robin Laplacian is shown to be maximal for the disk among simply-connected planar domains of fixed area when the Robin parameter is scaled by perimeter in the form $\alpha/L(\Omega)$, and $\alpha$ lies between…

Spectral Theory · Mathematics 2019-03-05 Pedro Freitas , Richard S. Laugesen

For a bounded domain $\Omega$ with a piecewise smooth boundary in an $n$-dimensional Euclidean space $\mathbf{R}^{n}$, we study eigenvalues of the Dirichlet eigenvalue problem of the Laplacian. First we give a general inequality for…

Differential Geometry · Mathematics 2011-06-09 Qing-Ming Cheng , Xuerong Qi

In this paper, we obtain the upper bounds for the Hausdorff measures of nodal sets of eigenfunctions with the Robin boundary conditions, i.e., \begin{equation*} {\left\{\begin{array}{l} \triangle u+\lambda u=0,\quad in\quad \Omega,\\…

Analysis of PDEs · Mathematics 2018-01-09 Fang Liu , Long Tian , Xiaoping Yang

In this article, we investigate the existence and multiplicity of solutions to the Robin problem \begin{equation*} \begin{cases} -\Delta u = \lambda f(u) & \text{in } \Omega, \frac{\partial u}{\partial \nu} + \gamma u=0 & \text{on }…

Analysis of PDEs · Mathematics 2025-12-01 José Carmona Tapia , Antonio J. Martínez Aparicio , Pedro J. Martínez-Aparicio

In this paper, we study the existence and the summability of solutions to a Robin boundary value problem whose prototype is the following: $$ \begin{cases} -\text{div}(b(|u|)\nabla u)=f &\text{in }\Omega,\\[.2cm] \displaystyle\frac{\partial…

Analysis of PDEs · Mathematics 2024-07-16 Francesco Della Pietra , Giuseppina di Blasio , Teresa Radice

Let $\Omega$ be a bounded, smooth domain of $\mathbb R^N$, $N\ge 2$. In this paper, we prove some inequalities involving the first Robin eigenvalue of the $p$-laplacian operator. In particular, we prove an upper bound for the first Robin…

Analysis of PDEs · Mathematics 2025-04-02 Rosa Barbato , Francesco Della Pietra

We present some new bounds for the first Robin eigenvalue with a negative boundary parameter. These include the constant volume problem, where the bounds are based on the shrinking coordinate method, and a proof that in the fixed perimeter…

Spectral Theory · Mathematics 2018-11-26 Pedro R. S. Antunes , Pedro Freitas , David Krejcirik

We consider the eigenvalues of the magnetic Laplacian on a bounded domain $\Omega$ of $\mathbb R^2$ with uniform magnetic field $\beta>0$ and magnetic Neumann boundary conditions. We find upper and lower bounds for the ground state energy…

Spectral Theory · Mathematics 2023-05-05 Bruno Colbois , Corentin Léna , Luigi Provenzano , Alessandro Savo

Let $\Omega\subset \mathbb{R}^n$ be a bounded $C^1$ domain and $p>1$. For $\alpha>0$, define the quantity \[ \Lambda(\alpha)=\inf_{u\in W^{1,p}(\Omega),\, u\not\equiv 0} \Big(\int_\Omega |\nabla u|^p\,\mathrm{d}x - \alpha…

Analysis of PDEs · Mathematics 2020-07-29 Konstantin Pankrashkin

The third eigenvalue of the Robin Laplacian on a simply-connected planar domain of given area is bounded above by the third eigenvalue of a disjoint union of two disks, provided the Robin parameter lies in a certain range and is scaled in…

Spectral Theory · Mathematics 2019-08-01 Alexandre Girouard , Richard S. Laugesen

We study the spectrum of the Laplacian on the hemisphere with Robin boundary conditions. It is found that the eigenvalues fall into small clusters around the Neumann spectrum, and satisfy a Szeg\H{o} type limit theorem. Sharp upper and…

Spectral Theory · Mathematics 2020-09-01 Zeév Rudnick , Igor Wigman
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