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We are concerned with the dependence of the lowest positive eigenvalue of the Dirac operator on the geometry of rectangles, subject to infinite-mass boundary conditions. We conjecture that the square is a global minimiser both under the…

Spectral Theory · Mathematics 2022-08-22 Philippe Briet , David Krejcirik

This paper aims to show that, in the limit of strong magnetic fields, the optimal domains for eigenvalues of magnetic Laplacians tend to exhibit symmetry. We establish several asymptotic bounds on magnetic eigenvalues to support this…

Spectral Theory · Mathematics 2025-09-11 Vladimir Lotoreichik , Léo Morin

We investigate how the lowest eigenvalue of a magnetic Laplacian depends on the geometry of a planar domain with a disk shaped hole, where the magnetic field is generated by a singular flux. Under Dirichlet boundary conditions on the inner…

Analysis of PDEs · Mathematics 2025-05-14 Mrityunjoy Ghosh , Ayman Kachmar

This paper concerns the shape optimization problem of minimizing the ground state energy of the magnetic Dirichlet Laplacian with constant magnetic field among three-dimensional domains of fixed volume. In contrast to the two-dimensional…

Mathematical Physics · Physics 2025-11-14 Matthias Baur

Motivated by relativistic materials, we develop a numerical scheme to support existing or state new conjectures in the spectral optimisation of eigenvalues of the Dirac operator, subject to infinite-mass boundary conditions. We study the…

Optimization and Control · Mathematics 2025-02-05 Pedro R. S. Antunes , Francisco Bento , David Krejcirik

We present numerical minimizers for the first seven eigenvalues of the magnetic Dirichlet Laplacian with constant magnetic field in a wide range of field strengths. Adapting an approach by Antunes and Freitas, we use gradient descent for…

Optimization and Control · Mathematics 2025-07-18 Matthias Baur

We prove various estimates for the first eigenvalue of the magnetic Dirichlet Laplacian on a bounded domain in two dimensions. When the magnetic field is constant, we give lower and upper bounds in terms of geometric quantities of the…

Spectral Theory · Mathematics 2015-01-23 Tomas Ekholm , Hynek Kovarik , Fabian Portmann

It is proved that the minimal Dirichlet eigenvalue of the Laplacian in an annulus is a monotonically decreasing function of the displacement of the center of the smaller disc. The maximal value of the minimal eigenvalue is attained when the…

Mathematical Physics · Physics 2007-05-23 A. G. Ramm , P. N. Shivakumar

In this paper we look for the domains minimizing the h-th eigenvalue of the Dirichlet-Laplacian $\lambda$ h with a constraint on the diameter. Existence of an optimal domain is easily obtained, and is attained at a constant width body. In…

Analysis of PDEs · Mathematics 2018-01-08 B Bogosel , A Henrot , I Lucardesi

We study the ground state energy of the Neumann magnetic Laplacian on planar domains. For a constant magnetic field we consider the question whether, under an assumption of fixed area, the disc maximizes this eigenvalue. More generally, we…

Spectral Theory · Mathematics 2018-05-16 Soeren Fournais , Bernard Helffer

We consider the magnetic Dirichlet Laplacian with constant magnetic field on domains of finite measure. First, in the case of a disk, we prove that the eigenvalue branches with respect to the field strength behave asymptotically linear with…

Spectral Theory · Mathematics 2025-01-20 Matthias Baur , Timo Weidl

We study the minimizers of the sum of the principal Dirichlet eigenvalue of the negative Laplacian and the perimeter with respect to a general norm in the class of Jordan domains in the plane. This is equivalent (modulo scaling) to…

Analysis of PDEs · Mathematics 2020-01-06 Marek Biskup , Eviatar B. Procaccia

We study the problem of minimizing the second Dirichlet eigenvalue for the Laplacian operator among sets of given perimeter. In two dimensions, we prove that the optimum exists, is convex, regular, and its boundary contains exactly two…

Analysis of PDEs · Mathematics 2010-11-29 Dorin Bucur , Giuseppe Buttazzo , Antoine Henrot

We consider the problem of minimising the $k$-th eigenvalue of the Laplacian with some prescribed boundary condition over collections of convex domains of prescribed perimeter or diameter. It is known that these minimisation problems are…

Spectral Theory · Mathematics 2024-02-07 Sam Farrington

We consider the Dirichlet Laplacian with a constant magnetic field in a two-dimensional domain of finite measure. We determine the sharp constants in semi-classical eigenvalue estimates and show, in particular, that Polya's conjecture is…

Mathematical Physics · Physics 2007-10-05 Rupert L. Frank , Michael Loss , Timo Weidl

We study the minimization of a spectral functional made as the sum of the first eigenvalue of the Dirichlet Laplacian and the relative strength of a Riesz-type interaction functional. We show that when the Riesz repulsion strength is below…

Analysis of PDEs · Mathematics 2021-03-09 Dario Mazzoleni , Berardo Ruffini

Among all triangles of given diameter, the equilateral triangle is shown to minimize the sum of the first $n$ eigenvalues of the Dirichlet Laplacian, for each $n \geq 1$. In addition, the first, second and third eigenvalues are each proved…

Spectral Theory · Mathematics 2010-08-10 Richard Laugesen , Bartlomiej Siudeja

The Dirichlet Laplacian between two parallel hypersurfaces in Euclidean spaces of any dimension in the presence of a magnetic field is considered in the limit when the distance between the hypersurfaces tends to zero. We show that the…

Mathematical Physics · Physics 2015-12-04 David Krejcirik , Nicolas Raymond , Matej Tusek

We consider the following eigenvalue optimization problem: Given a bounded domain $\Omega\subset\R^n$ and numbers $\alpha\geq 0$, $A\in [0,|\Omega|]$, find a subset $D\subset\Omega$ of area $A$ for which the first Dirichlet eigenvalue of…

Analysis of PDEs · Mathematics 2009-10-31 S. Chanillo , D. Grieser , M. Imai , K. Kurata , I. Ohnishi

We consider the problem of minimizing convex combinations of the first two eigenvalues of the Dirichlet-Laplacian among open sets of $R^N$ of fixed measure. We show that, by purely elementary arguments, based on the minimality condition, it…

Analysis of PDEs · Mathematics 2016-07-29 Dario Mazzoleni , Davide Zucco
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