Toeplitz Operators on Two Poly-Bergman-Type Spaces of the Siegel Domain $D_2 \subset \mathbb{C}^2$ with Continuous Nilpotent Symbols

Abstract: We describe certain $C^*$-algebras generated by Toeplitz operators with nilpotent symbols and acting on a poly-Bergman type space of the Siegel domain $D_{2} \subset \mathbb{C}^{2}$. Bounded measurable functions of the form $\tilde{c}(\zeta) = c(\text{Im}\, \zeta_{1}, \text{Im}\, \zeta_{2} - |\zeta_1|^{2})$ are called nilpotent symbols. In this work we consider symbols of the form $\tilde{a}(\zeta) = a(\text{Im}\, \zeta_1)$ and $\tilde{b}(\zeta) = b(\text{Im}\, \zeta_2 -|\zeta_1|^{2})$, where both limits $\lim\limits_{s\rightarrow 0^+} b(s)$ and $\lim\limits_{s\rightarrow +\infty} b(s)$ exist, and $a$ belongs to the set of piece-wise continuous functions on $\overline{\mathbb{R}}=[-\infty,+\infty]$ and with one-sided limits at $0$. We describe certain $C^*$-algebras generated by such Toeplitz operators that turn out to be isomorphic to subalgebras of $M_n(\mathbb{C}) \otimes C(\overline{\Pi})$, where $\overline{\Pi}=\overline{\mathbb{R}} \times \overline{\mathbb{R}}+$ and $\overline{\mathbb{R}}+=[0,+\infty]$.