D. Yakubovich

collaborators

5 papers

math.FA2026

Operators with small Kreiss constants

Nikolaos Chalmoukis, Georgios Tsikalas, Dmitry Yakubovich

We investigate matrices satisfying the Kreiss condition $∥ (z I - T)^{- 1} ∥ \leq \frac{K}{∣ z ∣ - 1}, ∣ z ∣ > 1,$ with $K$ lying arbitrarily close to $1.$ We provide lower bo…

math.CV2026

Self-improving estimates of growth of subharmonic and analytic functions

Glenier Bello, Dmitry Yakubovich

Given a bounded open subset $I^c ◯$ and closed subsets $A, B$ of $R^{k}$ , we discuss when an estimate $u (x) \leq g (d i s t (x, A \cup B))$ , $x \in I^c ◯ ∖ (A \cup B)$ , for a function $u…

math.FA2026

Embedding of Toeplitz operators with smooth symbols into strongly continuous semigroups

Emmanuel Fricain, Sophie Grivaux, MaÃ«va Ostermann +1

Using the model theory for Toeplitz operators with smooth symbols developed by the fourth author in the 80's, we study whether such operators $T_{F}$ can be embedded into a $C_{0}$ …

math.FA2025

Resolvent estimates for a function of a linear operator

Glenier Bello, Dmitry Yakubovich

Let $T$ be a bounded linear operator on a Banach space and $f$ an analytic function, defined on the spectrum of $T$ . We study the relations between the rate of growth of the resolv…

math.CV2025

Complete frequencies for Koenigs domains

We provide a complete characterization of those non-elliptic semigroups of holomorphic self-maps of the unit disc for which the linear span of eigenvectors of the generator of the…