1 citations · 1 across the 5 of their papers we have counts for
5 papers
Invariant subspaces for operators with spectrum containing the boundary of the numerical range
Vladimir Müller, Yuri Tomilov
We prove that a bounded Hilbert space operator has a nontrivial invariant subspace whenever its spectrum contains the topological boundary of its numerical range. We also give vari…
On similarity to contraction semigroups and tensor products, II: Infinite tensor products
Jesus Oliva-Maza, Yuri Tomilov
We develop a framework for infinite tensor products of Hilbert spaces, operators, and semigroups tailored to questions of similarity to contraction semigroups. On the operator-theo…
Similarity to contraction semigroups: structural properties, criteria, and applications to control theory
J. Oliva-Maza, Y. Tomilov
We reveal new aspects of the structure of Hilbert space -semigroups similar to semigroups of contractions. In particular, we prove that $\mathca…
On similarity to contraction semigroups and tensor products, I
J. Oliva-Maza, Y. Tomilov
In the context of finite tensor products of Hilbert spaces, we prove that similarity of a tensor product of operator semigroups to a contraction semigroup is equivalent to the corr…
Power-bounded operators and related norm estimates
Nigel Kalton, Stephen Montgomery-Smith, Krzysztof Oleszkiewicz +1
We consider whether L = limsup_{n to infty} n ||T^{n+1}-T^n|| < infty implies that the operator T is power bounded. We show that this is so if L<1/e, but it does not necessarily ho…