57 citations · 84 across the 29 of their papers we have counts for
34 papers
Hermitian indices and factorization of selfadjoint operators on a Kreĭn space
Michael A. Dritschel, Alejandra Maestripieri, James Rovnyak
The hermitian indices of a selfadjoint operator on a Kreĭn space are defined as geometric measures of positivity and negativity of the operator. A different pair o…
Rearrangement Invariant Orthogonal Sums in Krein Spaces. II
Michael A. Dritschel, Alejandra Maestripieri, James Rovnyak
Part I of the paper considered infinite orthogonal sums of regular subspaces in a Krein space (that is, of subspaces which are themselves Krein spaces). How precisely these sums sh…
Krein-Šmul'jan Theorem Revisited
Santiago gonzalez Zerbo, Alejandra Maestripieri, Francisco Martínez Pería
We present a generalization of Krein-Šmul'jan theorem which involves several operators. Given bounded selfadjoint operators acting on a Hilbert space $\mathcal{H…
Semiclosed multivalued projections
M. Laura Arias, Maximiliano Contino, Alejandra Maestripieri +1
A multivalued projection is an idempotent linear relation with invariant domain. We characterize multivalued projections that are operator ranges (called semiclosed) and provide se…
Quadratic programming with one quadratic constraint in Hilbert spaces
Santiago Gonzalez Zerbo, Alejandra Maestripieri, Francisco Martínez Pería
A quadratically constrained quadratic programming problem is considered in a Hilbert space setting, where neither the objective nor the constraint are convex functions. Necessary a…
Matrix representations of multivalued projections and least squares problems
Maria Laura Arias, Maximiliano Contino, Alejandra Maestripieri +1
Multivalued projections are applied to the study of weighted least squares solutions of linear relations equations (or inclusions) and some of its applications. To this end a matri…