Convergence of Iterations for Linear Equations

ISBN-13: 9783764328658 / Angielski / Miękka / 1993 / 180 str.

Olavi Nevanlinna

Opis

Discussing the convergence of Krylov subspace methods for solving fixed point problems, this work focuses on the dynamical aspects of the iteration processes and outlines all the phases of a lifespan of an iteration.

Spis treści

1. Motivation, problem and notation.- 1.1 Motivation.- 1.2 Problem formulation.- 1.3 Usual tools.- 1.4 Notation for polynomial acceleration.- 1.5 Minimal error and minimal residual.- 1.6 Approximation of the solution operator.- 1.7 Location of zeros.- 1.8 Heuristics.- Comments to Chapter 1.- 2. Spectrum, resolvent and power boundedness.- 2.1 The spectrum.- 2.2 The resolvent.- 2.3 The spectral mapping theorem.- 2.4 Continuity of the spectrum.- 2.5 Equivalent norms.- 2.6 The Yosida approximation.- 2.7 Power bounded operators.- 2.8 Minimal polynomials and algebraic operators.- 2.9 Quasialgebraic operators.- 2.10 Polynomial numerical hull.- Comments to Chapter 2.- 3. Linear convergence.- 3.1 Preliminaries.- 3.2 Generating functions and asymptotic convergence factors.- 3.3 Optimal reduction factor.- 3.4 Green’s function for G?.- 3.5 Optimal polynomials for.- 3.6 Simply connected G?(L).- 3.7 Stationary recursions.- 3.8 Simple examples.- Comments to Chapter 3.- 4. Sublinear convergence.- 4.1 Introduction.- 4.2 Convergence of Lk(L?1).- 4.3 Splitting into invariant subspaces.- 4.4 Uniform convergence.- 4.5 Nonisolated singularity and successive approximation.- 4.6 Nonisolated singularity and polynomial acceleration.- 4.7 Fractional powers of operators.- 4.8 Convergence of iterates.- 4.9 Convergence with speed.- Comments to Chapter 4.- 5. Superlinear convergence.- 5.1 What is superlinear.- 5.2 Introductory examples.- 5.3 Order and type.- 5.4 Finite termination.- 5.5 Lower and upper bounds for optimal polynomials.- 5.6 Infinite products.- 5.7 Almost algebraic operators.- 5.8 Estimates using singular values.- 5.9 Multiple clusters.- 5.10 Approximation with algebraic operators.- 5.11 Locally superlinear implies superlinear.- Comments to Chapter 5.- References.- Definitions.