2 citations · 2 across the 8 of their papers we have counts for
9 papers
Antitonicity property of the Moore-Penrose inverse for selfadjoint operators
Guillermina Fongi, M. Celeste Gonzalez
In this article we study the antitonicity property of the Moore-Penrose inverse in the class of selfadjoint operators, with respect to the Löwner order. For this purpose, we employ…
Proper splittings of Hermitian operators
Guillermina Fongi, María Celeste Gonzalez
In this article we deepen the study of proper splittings of Hilbert space operators, with special emphasis on proper splittings of Hermitian operators. On the one hand, we improve…
Proper splittings of Hilbert space operators
Guillermina Fongi, María Celeste Gonzalez
Proper splittings of operators are commonly used to study the convergence of iterative processes. In order to approximate solutions of operator equations, in this article we deal w…
Moore-Penrose inverse and partial orders on Hilbert space operators
Guillermina Fongi, María Celeste Gonzalez
In this article we explore several aspects concerning to the Moore-Penrose inverse of a bounded linear operator. On the one hand, we study monotonicity properties of the Moore-Penr…
Polyak's theorem on Hilbert spaces
Maximiliano Contino, Guillermina Fongi, Santiago Muro
We extend to infinite dimensional Hilbert spaces a celebrated result, due to B. Polyak, about the convexity of the joint image of quadratic functions. We give sufficient conditions…
Total least squares problems on infinite dimensional spaces
Maximiliano Contino, Guillermina Fongi, Alejandra Maestripieri +1
In this work we study weighted total least squares problems on infinite dimensional spaces. We show that in most cases this problem does not admit a solution (except in the trivial…
Global solutions of approximation problems in Hilbert spaces
Maximiliano Contino, Maria Eugenia Di Iorio y Lucero, Guillermina Fongi
We study three well-known minimization problems in Hilbert spaces: the weighted least squares problem and the related problems of abstract splines and smoothing. In each case we an…
The minus order and range additivity
Marko Djikic, Guillermina Fongi, Alejandra Maestripieri
We study the minus order on the algebra of bounded linear operators on a Hilbert space. By giving a characterization in terms of range additivity, we show that the intrinsic nature…
Weighted projections into closed subspaces
Gustavo Corach, Guillermina Fongi, Alejandra Maestripieri
In this paper we study -projections, i.e. operators of a Hilbert space $\HH$ which act as projections when a seminorm is considered in $\HH$. -projections were introduced by…