Free bianalytic maps between spectrahedra and spectraballs in a generic setting

Meric Augat, J. William Helton, Igor Klep +1

Given a tuple $E=(E_1,\dots ,E_g)$ of $d\times d$ matrices, the collection of those tuples of matrices $X=(X_1,\dots ,X_g)$ (of the same size) such that $\| \sum E_j\otimes X_j\|\le…