A characterization and representation of the generalized inverse A(2)T,S and its applications

AbstractThis paper presents an explicit expression for the generalized inverse A(2)T,S. Based on this, we established the characterization, the representation theorem and the limiting process for A(2)T,S. As an application, we estimate the error bound of the iterative method for approximating A(2)T,S

Saddle point problems, Bott-Duffin inverses, abstract splines and oblique projections

In this note, we present links between several different areas in numerical analysis and operator theory. More precisely, we show that several saddle point problems are solvable in the presence of a property (called compatibility) between a positive operator and a closed subspace of a Hilbert space, and the same happens with certain abstract spline problems. These notions are related to the generalized Bott?Duffin inverse.Fil: Arias, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática; ArgentinaFil: Corach, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática; Argentina. Universidad de Buenos Aires. Facultad de Ingenieria. Departamento de Matematicas; ArgentinaFil: Gonzalez, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática; Argentina. Universidad Nacional de General Sarmiento; Argentin

A matrix optimization problem

AbstractA minimization problem for a matrix-valued matrix function is considered. A duality theorem is proved. Some examples illustrate its applicability

Range additivity, shorted operator and the Sherman-Morrison-Woodbury formula

We say that two operators A, B have the range additivity property if R(A + B) = R(A) + R(B). In this article we study the relationship between range additivity, shorted operator and certain Hilbert space decomposition known as compatibility. As an application, we extend to infinite dimensional Hilbert space operators a formula by Fill and Fishkind related to the well-known Sherman-Morrison-Woodbury formula

Konzistentnost i problemi kompletiranja operatorskih matrica: doktorske disertacije

In this thesis different types of operator matrix completions have been studied, as well as consistency in invertibility and in Fredholmnes. The property consistency has been considered on Banach algebras in the sense of concsistency in invertibility and consistence in Fredholmnes. Result concering completions of operator matrices are linked to certain properties of a linear combination of two arbitrary Hilbert space operators. The properties studied in this thesis are: invertibility, injectivity, left (right) invertibility, closednes of range, consistency in invertibility of a linear combination of two arbitrary Hilbert space operators. Some of these results are applied to the study of the Generalized Bott-Duffin inverse, primarily to represent the Generalized Bott-Duffin inverse of bounded linear operator on a Hilbert space using an operator matrix. The obtained operator matrix representation of the Generalized Bott-Duffin inverse is a generalization of previous results