3 papers
math.FA2026
On the Cotlar-Stein lemma
Michael Hartz, Marcel Scherer
We give a direct proof of the Cotlar-Stein lemma, which does not rely on the power trick.
math.FA2023
Spectra of Quotient Modules
Michael Didas, Jörg Eschmeier, Michael Hartz +1
We determine the Taylor spectra of quotient tuples of the -shift on Drury-Arveson spaces with finite-dimensional coefficient spaces. We show the the Taylor spectrum can be descr…
math.FA2021
Essential spherical isometries
Marcel Scherer
A result due to Williams, Stampfli and Fillmore shows that an essential isometry on a Hilbert space is a compact perturbation of an isometry if and only if ind$(T…