4 papers
math.FA2017
On the generation of Arveson weakly continuous semigroups
Jean Esterle
We consider here one-parameter semigroups of bounded operators on a Banach space which are weakly continuous in the sense of Arveson. For such a semigrou…
math.FA2017
Estimates near the origin for functional calculus on analytic semigroups
I. Chalendar, J. Esterle, J. R. Partington
This paper provides sharp lower estimates near the origin for the functional calculus of a generator of an operator semigroup defined on a sector; here is given as…
math.FA2015
A short proof of the zero-two law for cosine functions
Jean Esterle
Let $(C(t))\in\mathbb{R}}$ be a cosine function in a unital Banach algebra. We give a simple proof of the fact that if lim sup$\_{t\to 0}\vert C(t)-1\_A\vert\textless{}2,$ then $li…
math.FA2015
A zero-sqrt(5)/ 2 law for cosine families
Jean Esterle
Let and let be the largest constant such that $sup\vert cos(na)-cos(nb)\vert \textless{} k(a)$ for implies that We show that if a…