3 papers
math.FA2026
Best approximants relative to a C-subalgebra, joint numerical range and subdifferentials
Tamara Bottazzi, Alejandro Varela
We study the minimality of Hermitian matrices respect to a -subalgebra of in the spectral norm, that is \[\|A\|\leq \|A+B\|,\ \…
math.FA2025
Semi-inner product and angles in Schatten ideals
Tamara Bottazzi, Cristian Conde
In this paper, we investigate the Schatten -class ideals for as semi-inner product spaces in the sense of Giles and Lumer. Within this framework, we explore several geome…
math.FA2024
Minimal compact operators, subdifferential of the maximum eigenvalue and semi-definite programming
Tamara Bottazzi, Alejandro Varela
We formulate the issue of minimality of self-adjoint operators on a Hilbert space as a semi-definite problem, linking the work by Overton in [1] to the characterization of minimal…