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The aim of the paper is to derive spectral estimates on the eigenvalue moments of the magnetic Dirichlet Laplacian defined on the two-dimensional disk with a radially symmetric magnetic field.

Spectral Theory · Mathematics 2016-08-17 Diana Barseghyan , Francoise Truc

We consider the magnetic Laplacian with the homogeneous magnetic field in two and three dimensions. We prove that the $(k+1)$-th magnetic Neumann eigenvalue of a bounded convex planar domain is not larger than its $k$-th magnetic Dirichlet…

Spectral Theory · Mathematics 2024-05-21 Vladimir Lotoreichik

This paper is about a shape optimization problem related to the Dirichlet Laplacian eingevalues in the Euclidean plane. More precisely we study the shape of the minimizer in the class of open sets of constant width. We prove that the disk…

Spectral Theory · Mathematics 2018-01-15 Zakaria Fattah , Mohamed Berrada

The first two eigenvalues of the Robin Laplacian are investigated along with their gap and ratio. Conjectures by various authors for arbitrary domains are supported here by new results for rectangular boxes. Results for rectangular domains…

Spectral Theory · Mathematics 2020-01-08 Richard S. Laugesen

We derive a lower bound to the spectral threshold of the Dirichlet Laplacian in tubular neighbourhoods of constant radius about complete surfaces. This lower bound is given by the lowest eigenvalue of a one-dimensional operator depending on…

Mathematical Physics · Physics 2017-09-08 Pedro Freitas , David Krejcirik

The sum of the first n energy levels of the planar Laplacian with constant magnetic field of given total flux is shown to be maximal among triangles for the equilateral triangle, under normalization of the ratio (moment of inertia)/(area)^3…

Analysis of PDEs · Mathematics 2015-05-27 Richard S. Laugesen , Jian Liang , Arindam Roy

We consider the problem of geometric optimisation of the lowest eigenvalue of the Laplacian in the exterior of a compact set in any dimension, subject to attractive Robin boundary conditions. As an improvement upon our previous work…

Spectral Theory · Mathematics 2020-06-26 David Krejcirik , Vladimir Lotoreichik

We consider the Dirac operator on right triangles, subject to infinite-mass boundary conditions. We conjecture that the lowest positive eigenvalue is minimised by the isosceles right triangle both under the area or perimeter constraints. We…

Spectral Theory · Mathematics 2023-04-12 Tuyen Vu

We study the behaviour of extremal eigenvalues of the Dirichlet biharmonic operator over rectangles with a given fixed area. We begin by proving that the principal eigenvalue is minimal for a rectangle for which the ratio between the…

Spectral Theory · Mathematics 2019-08-20 D. Buoso , P. Freitas

For a two-dimensional curved waveguide, it is well known that the spectrum of the Dirichlet Laplacian is unstable. Any perturbation of the straight strip produces eigenvalues below the essential spectrum. In this paper, a magnetic field is…

Spectral Theory · Mathematics 2025-03-03 Diana Barseghyan , Swanhild Bernstein , Baruch Schneider , Martha Lina Zimmermann

We establish geometric lower bounds for the smallest positive eigenvalue of the Hodge Laplacian in the class of non-convex domains given by Euclidean annular regions with a convex outer boundary and a spherical inner boundary. These bounds…

Differential Geometry · Mathematics 2026-04-21 Tirumala Chakradhar , Pierre Nicolle-Guerini

We consider the problem of geometric optimisation of the lowest eigenvalue of the Laplacian in the exterior of a compact planar set, subject to attractive Robin boundary conditions. Under either a constraint of fixed perimeter or area, we…

Spectral Theory · Mathematics 2018-11-26 David Krejcirik , Vladimir Lotoreichik

The paper concerns the analysis of global minimizers of a Dirichlet-type energy functional defined on the space of vector fields $H^1(S,T)$, where $S$ and $T$ are surfaces of revolution. The energy functional we consider is closely related…

Analysis of PDEs · Mathematics 2023-07-25 Giovanni Di Fratta , Valeriy Slastikov , Arghir Zarnescu

This paper studies the optimization of the lowest eigenvalue of the magnetic Steklov problem on planar domains. In the bounded domain setting and for magnetic fields of moderate strengths, we prove that among all simply-connected smooth…

Analysis of PDEs · Mathematics 2026-02-20 Ayman Kachmar , Vladimir Lotoreichik

The aim of this paper is to establish estimates of the lowest eigenvalue of the Neumann realization of $(i\nabla+B\textbf{A})^2$ on an open bounded subset of $\mathbb{R}^2$ $\Omega$ with smooth boundary as $B$ tends to infinity. We…

Mathematical Physics · Physics 2015-05-13 Nicolas Raymond

On a metric measure space $X$ that supports a regular, strongly local resistance form we consider a magnetic energy form that corresponds to the magnetic Laplacian for a particle confined to $X$. We provide sufficient conditions for…

Mathematical Physics · Physics 2016-09-01 Michael Hinz , Luke Rogers

We study the magnetic Laplacian in a two-dimensional exterior domain with Neumann boundary condition and uniform magnetic field. For the exterior of the disk we establish accurate asymptotics of the low-lying eigenvalues in the weak…

Spectral Theory · Mathematics 2024-05-29 Ayman Kachmar , Vladimir Lotoreichik , Mikael Sundqvist

Given the Laplacian on a planar, convex domain with piecewise linear boundary subject to mixed Dirichlet-Neumann boundary conditions, we provide a sufficient condition for its lowest eigenvalue to dominate the lowest eigenvalue of the…

Spectral Theory · Mathematics 2017-10-03 Jonathan Rohleder

We consider a shape optimization problem related to the persistence threshold for a biological species, the unknown shape corresponding to the zone of the habitat which is favorable to the population. Analytically, this translates in the…

Analysis of PDEs · Mathematics 2023-04-18 Lorenzo Ferreri , Gianmaria Verzini

We consider the problem of minimizing the weighted Dirichlet energy between homeomorphisms of planar annuli. A known challenge lies in the case when the weight $\lambda$ depends on the independent variable $z$. We prove that for an…

Complex Variables · Mathematics 2019-04-18 Aleksis Koski , Jani Onninen