Unitary invariants on the unit ball of $B(\mathcal {H})^n$
Unitary invariants on the unit ball of $B(\mathcal {H})^n$
In this paper, we introduce a unitary invariant \[ \Gamma :[B(\mathcal {H})^n]_1^-\to \mathbb {N}_\infty \times \mathbb {N}_\infty \times \mathbb {N}_\infty ,\qquad \mathbb {N}_\infty :=\mathbb {N}\cup \{ \infty \},\] defined in terms of the characteristic function $\Theta _T$, the noncommutative Poisson kernel $K_T$, and the defect operator $\Delta _T$ associated with …