TY - JOUR ID - Cho2021 LB - Cho2021 AU - Cho, Ilwoo TI - Spectral properties of certain operators on the free Hilbert space \(\mathfrak{F}[H_{1},...,H_{N}]\) and the semicircular law ST - Spectral properties of certain operators on the free Hilbert space \(\mathfrak{F}[H_{1},...,H_{N}]\) and the semicircular law JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2021 VL - 41 IS - 6 SP - 755 EP - 803 DO - https://doi.org/10.7494/OpMath.2021.41.6.755 UR - https://doi.org/10.7494/OpMath.2021.41.6.755 AB - In this paper, we fix \(N\)-many \(l^2\)-Hilbert spaces \(H_k\) whose dimensions are \(n_{k} \in \mathbb{N}^{\infty}=\mathbb{N} \cup \{\infty\}\), for \(k=1,\ldots,N\), for \(N \in \mathbb{N}\setminus\{1\}\). And then, construct a Hilbert space \(\mathfrak{F}=\mathfrak{F}[H_{1},\ldots,H_{N}]\) induced by \(H_{1},\ldots,H_{N}\), and study certain types of operators on \(\mathfrak{F}\). In particular, we are interested in so-called jump-shift operators. The main results (i) characterize the spectral properties of these operators, and (ii) show how such operators affect the semicircular law induced by \(\bigcup^N_{k=1} \mathcal{B}_{k}\), where \(\mathcal{B}_{k}\) are the orthonormal bases of \(H_{k}\), for \(k=1,\ldots,N\). KW - separable Hilbert spaces KW - free Hilbert spaces KW - jump operators KW - shift operators KW - jump-shift operators KW - semicircular elements SN - 1232-9274 ER -