Abstract:
Let $f$ be a function belonging to the nonhomogeneous analytic Besov space
$(\mathrm{\text{Б}}_{\infty,1}^1)_+(\mathbb{R}^2)$.
For a pair $(L,M)$ of not necessarily commuting maximal dissipative
operators, the function $f(L,M)$ is introduced as a densely defined
linear.
For $p\in[1,2]$, we prove that if $(L_1,M_1)$ and $(L_2,M_2)$ are pairs of
not necessarily commuting maximal dissipative operators such that the two
difeerences $L_1-L_2$ и $M_1-M_2$
belong to the Schatten–von Neumann class $\mathbf{S}_p$, then for every $f$ in
$(\mathrm{\text{Б}}_{\infty,1}^1)_+(\mathbb{R}^2)$ the operator difference $f(L_1,M_1)-f(L_2,M_2)$ belongs to
$\mathbf{S}_p$ and the following Lipschitz-type estimate holds true:
$
\|f(L_1,M_1)-f(L_2,M_2)\|_{\mathbf{S}_p}
\le\mathrm{const}\,\|f\|_{\mathrm{\text{Б}}_{\infty,1}^1}\max\big\{\|L_1-L_2\|_{\mathbf{S}_p},\|M_1-M_2\|_{\mathbf{S}_p}\big\}.
$
Keywords:dissipative operator, Haagerup tensor product, Haagerup-type tensor products, semispectral measure, Besov classes, functions of noncommuting operators, Lipschitz-type estimates for functions of operators, Schatten–von Neumann classes.