RUS  ENG
Full version
JOURNALS // Itogi Nauki i Tekhniki. Sovremennaya Matematika i ee Prilozheniya. Tematicheskie Obzory // Archive

Itogi Nauki i Tekhniki. Sovrem. Mat. Pril. Temat. Obz., 2021 Volume 193, Pages 69–86 (Mi into801)

On the inverse closedness of the subalgebra of local Hilbert–Schmidt operators

E. Yu. Guseva

Voronezh State University

Abstract: A local Hilbert–Schmidt operator is an operator of the form
\begin{equation*} (Tx)(t)=\int\limits_{-\infty}^{+\infty}k(t,s)x(s)ds \end{equation*}
with a measurable kernel $k:\mathbb{R}^2\to\mathbb{C}$ under the condition that
\begin{equation*} \int\limits_a^{b}\int\limits_a^{b}|k(t,s)|^2 ds dt<\infty \end{equation*}
for all $-\infty<a<b<+\infty$. We prove that, under some additional conditions that provide the action of the operator $T$ in $L_2(\mathbb{R},\mathbb{C})$, the invertibility of the operator $\mathbf{1}+T$ implies that the inverse operator has the form $\mathbf{1}+T_1$, where $T_1$ is also a local Hilbert–Schmidt operator whose kernel $S$ satisfies the same conditions.

Keywords: Hilbert–Schmidt operator, full subalgebra, difference operator, convolution operator, operator majorized by a convolution.

UDC: 517.984.4

MSC: 47L80, 47B10, 35P05

DOI: 10.36535/0233-6723-2021-193-69-86



© Steklov Math. Inst. of RAS, 2024