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Related papers: Dislocation Defects and Diophantine Approximation

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We prove a Diophantine approximation inequality for closed subschemes on surfaces which can be viewed as a joint generalization of recent inequalities of Ru-Vojta and Heier-Levin in this context. As applications, we study various…

Number Theory · Mathematics 2024-06-28 Keping Huang , Aaron Levin , Zheng Xiao

We study the relation between the diameter, the first positive eigenvalue of the discrete $p$-Laplacian and the $\ell_p$-distortion of a finite graph. We prove an inequality relating these three quantities and apply it to families of Cayley…

Group Theory · Mathematics 2011-07-13 Rostislav I. Grigorchuk , Piotr W. Nowak

The main issue in this paper is to discuss a parity property that appears in the expressions for the distorted spectrum of the thermal Sunyaev-Zel'dovich effect. When using the convolution integrals method involving scattering laws we argue…

Astrophysics · Physics 2011-04-11 A. Sandoval-Villalbazo , L. S. Garcia-Colin

In this paper, we study a generalized finite element method for solving second-order elliptic partial differential equations with rough coefficients. The method uses local approximation spaces computed by solving eigenvalue problems on…

Numerical Analysis · Mathematics 2025-07-17 Christian Alber , Peter Bastian , Moritz Hauck , Robert Scheichl

The spectral properties of the Schr\"odinger operator $T_ty= -y''+q_ty$ in $L^2(\R)$ are studied, with a potential $q_t(x)=p_1(x), x<0, $ and $q_t(x)=p(x+t), x>0, $ where $p_1, p$ are periodic potentials and $t\in \R$ is a parameter of…

Spectral Theory · Mathematics 2007-05-23 Evgeny Korotyaev

Large-scale eigenvalue problems arise in various fields of science and engineering and demand computationally efficient solutions. In this study, we investigate the subspace approximation for parametric linear eigenvalue problems, aiming to…

In this work, we introduce a new difference equation which is discrete analogue of Diffusion differential equation and analyze some essential spectral properties, Diffusion difference operator is self-adjoint, eigenvalues of this problem…

Spectral Theory · Mathematics 2017-05-03 Erdal Bas , Ramazan Ozarslan

In this paper, using new correction to the Crouzeix-Raviart finite element eigenvalue approximations, we obtain lower eigenvalue bounds for the Steklov eigenvalue problem with variable coefficients on d-dimensional domains (d = 2,3). In…

Numerical Analysis · Mathematics 2019-08-27 Yu Zhang , Hai Bi , Yidu Yang

This paper investigates the stability properties of the spectrum of the classical Steklov problem under domain perturbation. We find conditions which guarantee the spectral stability and we show their optimality. We emphasize the fact that…

Analysis of PDEs · Mathematics 2021-03-10 Alberto Ferrero , Pier Domenico Lamberti

We discuss a method based on a segmentary approximation of solutions of the Schr\"odinger by quadratic splines, for which the coefficients are determined by a variational method that does not require the resolution of complicated algebraic…

Quantum Physics · Physics 2018-09-26 Manuel Gadella , Luis Pedro Lara

A spatially localized initial condition for an energy-conserving wave equation with periodic coefficients disperses (spatially spreads) and decays in amplitude as time advances. This dispersion is associated with the continuous spectrum of…

Mathematical Physics · Physics 2021-10-01 Vincent Duchêne , Iva Vukićević , Michael I. Weinstein

The celebrated Cwikel-Lieb_Rozenblum inequality gives an upper estimate for the number of negative eigenvalues of Schroedinger operators in dimension three and higher. The situation is much more difficult in the two dimensional case. There…

Spectral Theory · Mathematics 2016-09-27 Martin Karuhanga

Utilizing an appropriate ansatz to the wave function, we reproduce the exact bound-state solutions of the radial Schrodinger equation to various exactly solvable sextic anharmonic oscillator and confining perturbed Coulomb models in…

Quantum Physics · Physics 2009-11-13 Sameer M. Ikhdair

In this paper, we give a definition of Diophantine points of type $\gamma$ for $\gamma\geq0$ in a homogeneous space $G/\Gamma$, and compute the Hausdorff dimension of the subset of points which are not Diophantine of type $\gamma$ when $G$…

Dynamical Systems · Mathematics 2019-08-06 Cheng Zheng

In the present paper we establish bounds for the size of the spectral gap for actions of algebraic groups on certain homogeneous spaces. Our approach is based on estimating operator norms of suitable averaging operators, and we develop…

Number Theory · Mathematics 2022-03-08 Alexander Gorodnik , Amos Nevo

This paper considers the propagation of TE-modes in photonic crystal waveguides. The waveguide is created by introducing a linear defect into a periodic background medium. Both the periodic background problem and the perturbed problem are…

Spectral Theory · Mathematics 2019-01-17 B. M. Brown , V. Hoang , M. Plum , M. Radosz , I. Wood

Defect cavities in 3D photonic crystal can trap and store light in the smallest volumes allowable in dielectric materials, enhancing non-linearities and cavity QED effects. Here, we study inverse rod-connected diamond (RCD) crystals…

We tried to determine the range of validity of a recently proposed modification of the Hellmann potential that leads to analytical eigenvalues and eigenfunctions. We discuss the difficulties that we found in the analysis of the main…

Quantum Physics · Physics 2014-11-19 Paolo Amore , Francisco M. Fernández

Thanks to recent advances in parametric geometry of numbers, we know that the spectrum of any set of $m$ exponents of Diophantine approximation to points in $\mathbb{R}^n$ (in a general abstract setting) is a compact connected subset of…

Number Theory · Mathematics 2022-02-02 Martin Rivard-Cooke , Damien Roy

We are interested in diagonal perturbations of a periodic Jacobi operator that introduce embedded eigenvalues in its essential spectrum. Embedding multiple points in the essential spectrum has been known to be difficult, given that…

Spectral Theory · Mathematics 2018-10-05 Wencai Liu , Darren C. Ong