3 papers
math.FA2025
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…
math.OC2023
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…
math.FA2014
The effect of finite rank perturbations on Jordan chains of linear operators
Jussi Behrndt, Leslie Leben, Francisco Martínez Pería +1
A general result on the structure and dimension of the root subspaces of a matrix or a linear operator under finite rank perturbations is proved: The increase of dimension from the…