Results 31 to 40 of about 130,152 (295)
Perturbations of nonlinear eigenvalue problems
Communications on Pure & Applied Analysis, 2019 arXiv admin note: text overlap with arXiv:1804 ...
Papageorgiou, Nikolaos S. +2 more
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Analytic Perturbation Theory and Renormalization Analysis of Matter Coupled to Quantized Radiation [PDF]
, 2008 For a large class of quantum mechanical models of matter and radiation we develop an analytic perturbation theory for non-degenerate ground states.
Griesemer, Marcel, Hasler, David
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On the Perturbed Eigenvalue Problem
Journal of Mathematical Analysis and Applications, 1995 The author considers the perturbed eigenvalue problem \(L(x) v(x)= \lambda(x) v(x)\) near \(0= x\in \mathbb{R}\) with \(L(x)\) a Fredholm operator of index zero. Using the implicit function theorem and the bordering lemma, he derives a necessary and sufficient smoothness condition for the characteristic pairs \((\lambda(x), v(x))\) with eigenvalue ...
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Eigenvalues, pseudospectrum and structured perturbations [PDF]
Linear Algebra and its Applications, 2006 AbstractWe investigate the behavior of eigenvalues under structured perturbations. We show that for many common structures such as (complex) symmetric, Toeplitz, symmetric Toeplitz, circulant and others the structured condition number is equal to the unstructured condition number for normwise perturbations, and prove similar results for real ...
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Perturbation of eigenvalues of the Klein–Gordon operators [PDF]
Revista Matemática Complutense, 2019 We prove inclusion theorems for both spectra and essential spectra as well as two-sided bounds for isolated eigenvalues for Klein-Gordon type Hamiltonian operators. We first study operators of the form $JG$, where $J$, $G$ are selfadjoint operators on a Hilbert space, $J = J^* = J^{-1}$ and $G$ is positive definite and then we apply these results to ...
Ivica Nakić, Krešimir Veselić
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Boundary Value Problems, 2010 We applied the variational iteration method and the homotopy perturbation method to solve Sturm-Liouville eigenvalue and boundary value problems. The main advantage of these methods is the flexibility to give approximate and exact solutions to both ...
R. Darzi, A. Neamaty
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Positive solutions for perturbations of the Robin eigenvalue problem plus an indefinite potential
, 2019 We study perturbations of the eigenvalue problem for the negative Laplacian plus an indefinite and unbounded potential and Robin boundary condition. First we consider the case of a sublinear perturbation and then of a superlinear perturbation.
Papageorgiou, N. S. +2 more
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Analysis of alpha modes in multigroup diffusion
Nuclear Engineering and Technology, 2017 The alpha eigenvalue problem in multigroup neutron diffusion is studied with particular attention to the theoretical analysis of the model. Contrary to previous literature results, the existence of eigenvalue and eigenflux clustering is investigated here
Richard Sanchez +3 more
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An approximate diagonalization method for large scale Hamiltonians
, 2012 An approximate diagonalization method is proposed that combines exact diagonalization and perturbation expansion to calculate low energy eigenvalues and eigenfunctions of a Hamiltonian.
Amin, Mohammad H. +3 more
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Multiple-rank modification of symmetric eigenvalue problem
MethodsX, 2018 Rank-1 modifications applied k-times (k > 1) often are performed to achieve a rank-k modification. We propose a rank- k modification for enhancing computational efficiency. As the first step toward a rank- k modification, an algorithm to perform a rank-2
HyungSeon Oh, Zhe Hu
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