8 citations · 22 across the 8 of their papers we have counts for
10 papers
Spectral properties of unbounded J-self-adjoint matrices
Matthias Langer, Michael Strauss
We study the spectrum of unbounded J-self-adjoint block operator matrices. In particular, we prove enclosures for the spectrum, provide a sufficient condition for the spectrum bein…
A new approach to spectral approximation
Michael Strauss
A new technique for approximating eigenvalues and eigenvectors of a self-adjoint operator is presented. The method does not incur spectral pollution, uses trial spaces from the for…
Spectral enclosure and superconvergence for eigenvalues in gaps
James Hinchcliffe, Michael Strauss
We consider the problem of how to compute eigenvalues of a self-adjoint operator when a direct application of the Galerkin (finite-section) method is unreliable. The last two decad…
Spectral estimates and basis properties for self-adjoint block operator matrices
Michael Strauss
In the first part of this manuscript a relationship between the spectrum of self-adjoint operator matrices and the spectra of their diagonal entries is found. This leads to enclosu…
The Second Order Spectrum and Optimal Convergence
Michael Strauss
The method of second order relative spectra has been shown to reliably approximate the discrete spectrum for a self-adjoint operator. We extend the method to normal operators and f…
Triple Variational Principles for Self-Adjoint Operator Functions
Matthias Langer, Michael Strauss
For a very general class of unbounded self-adjoint operator function we prove upper bounds for eigenvalues which lie within arbitrary gaps of the essential spectrum. These upper bo…
The Galerkin Method for Perturbed Self-Adjoint Operators and Applications
Michael Strauss
We consider the Galerkin method for approximating the spectrum of an operator where is semi-bounded self-adjoint and satisfies a relative compactness condition. We sh…
Eigenvalue enclosures and convergence for the linearized MHD operator
Lyonell Boulton, Michael Strauss
We discuss how to compute certified enclosures for the eigenvalues of benchmark linear magnetohydrodynamics operators in the plane slab and cylindrical pinch configurations. For th…
On the convergence of second order spectra and multiplicity
Lyonell Boulton, Michael Strauss
Let A be a self-adjoint operator acting on a Hilbert space. The notion of second order spectrum of A relative to a given finite-dimensional subspace L has been studied recently in…
Stability of Quadratic Projection Methods
Lyonell Boulton, Michael Strauss
In this paper we discuss the stability of an alternative pollution-free procedure for computing spectra. The main difference with the Galerkin method lies in the fact that it gives…