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Related papers: Spectral optimisation of Dirac rectangles

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We consider Dirac operators on the half-line, subject to generalised infinite-mass boundary conditions. We derive sufficient conditions which guarantee the stability of the spectrum against possibly non-self-adjoint potential perturbations…

Spectral Theory · Mathematics 2025-02-05 David Kramar , David Krejcirik

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 present some new problems in spectral optimization. The first one consists in determining the best domain for the Dirichlet energy (or for the first eigenvalue) of the {\it metric Laplacian}, and we consider in particular Riemannian or…

Optimization and Control · Mathematics 2013-04-17 Giuseppe Buttazzo , Bozhidar Velichkov

This work considers the problem of super-resolution. The goal is to resolve a Dirac distribution from knowledge of its discrete, low-pass, Fourier measurements. Classically, such problems have been dealt with parameter estimation methods.…

Information Theory · Computer Science 2015-02-02 Ayush Bhandari , Yonina Eldar , Ramesh Raskar

This paper proposes novel algorithm for non-convex multimodal constrained optimisation problems. It is based on sequential solving restrictions of problem to sections of feasible set by random subspaces (in general, manifolds) of low…

Optimization and Control · Mathematics 2023-03-28 Dmitry A. Pasechnyuk , Alexander Gornov

Maximization and minimization problems of the principle eigenvalue for divergence form second order elliptic operators with the Dirichlet boundary condition are considered. The principal eigen map of such elliptic operators is introduced…

Optimization and Control · Mathematics 2019-08-28 Hongwei Lou , Jiongmin Yong

We study the problem of optimizing the eigenvalues of the Dirichlet Laplace operator under perimeter constraint. We prove that optimal sets are analytic outside a closed singular set of dimension at most $d-8$ by writing a general…

Optimization and Control · Mathematics 2017-06-29 Beniamin Bogosel

We consider a special nonconvex quartic minimization problem over a single spherical constraint, which includes the discretized energy functional minimization problem of non-rotating Bose-Einstein condensates (BECs) as one of the important…

Numerical Analysis · Mathematics 2020-12-04 Pengfei Huang , Qingzhi Yang , Yuning Yang

The inverse spectral theory for a self-adjoint one-dimensional Dirac operator associated periodic potentials is formulated via a Riemann-Hilbert problem approach. The resulting formalism is also used to solve the initial value problem for…

Analysis of PDEs · Mathematics 2026-01-12 Gino Biondini , Zechuan Zhang

We consider the problem of geometric optimization for the lowest eigenvalue of the two-dimensional Schr\"odinger operator with an attractive $\delta'$-interaction of a fixed strength, the support of which is a $C^2$-smooth contour. Under…

Spectral Theory · Mathematics 2018-10-15 Vladimir Lotoreichik

In this survey we consider polynomial optimization problems, asking to minimize a polynomial function over a compact semialgebraic set, defined by polynomial inequalities. This models a great variety of (in general, nonlinear nonconvex)…

Optimization and Control · Mathematics 2025-01-16 Monique Laurent , Lucas Slot

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

In this work, a complete solution of the inverse spectral problem for a class of Dirac differential equations system is given by spectral data (eigenvalues and normalizing numbers). As a direct problem, the eigenvalue problem is solved: the…

Spectral Theory · Mathematics 2015-10-13 Khanlar R. Mamedov , Ozge Akcay

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 describe a new family of examples of hypersurfaces in the sphere satisfying the limiting-case in C. B\"ar's extrinsic upper bound for the smallest eigenvalue of the Dirac operator.

Differential Geometry · Mathematics 2007-05-23 Nicolas Ginoux

Let $\Omega\subset\mathbb{R}^N$, $N\geq 2$, be an open bounded connected set. We consider the fractional weighted eigenvalue problem $(-\Delta)^s u =\lambda \rho u$ in $\Omega$ with homogeneous Dirichlet boundary condition, where…

Analysis of PDEs · Mathematics 2019-04-08 Claudia Anedda , Fabrizio Cuccu , Silvia Frassu

A computer-assisted proof is proposed for the Laplacian eigenvalue minimization problems over triangular domains under diameter constraints. The proof utilizes recently developed guaranteed computation methods for both eigenvalues and…

Numerical Analysis · Mathematics 2022-09-30 Ryoki Endo , Xuefeng Liu

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

We study the (massless) Dirac operator on a 3-sphere equipped with Riemannian metric. For the standard metric the spectrum is known. In particular, the eigenvalues closest to zero are the two double eigenvalues +3/2 and -3/2. Our aim is to…

Spectral Theory · Mathematics 2018-08-10 Yan-Long Fang , Michael Levitin , Dmitri Vassiliev

For closed connected Riemannian spin manifolds an upper estimate of the smallest eigenvalue of the Dirac operator in terms of the hyperspherical radius is proved. When combined with known lower Dirac eigenvalue estimates, this has a number…

Differential Geometry · Mathematics 2024-08-09 Christian Baer