Elementary operators on Calkin algebras

• Main Author: Martin Mathieu
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Klaus; tylli
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.595.9135; http://www.maths.tcd.ie/pub/ims/bull46/S4602.pdf

This paper is dedicated to the memory of Professor Klaus Vala. Properties of elementary operators, especially on algebras of operators, have been vigorously studied over the past decades. It emerges that the situation of the Calkin algebra is full of surprises. In this setting, an elementary operator with dense range is surjective, and injectiv-ity entails boundedness below. In the case of Hilbert space, positivity implies complete positivity, and the norm and the cb-norm of every el-ementary operator coincide. We present an overview on some results of this flavour, in particular on recent extensions of the latter two results to antiliminal-by-abelian C*-algebras (obtained by Archbold, Somerset, and the author), and strong rigidity properties of the norm of elemen-tary operators on Calkin algebras due to Saksman and Tylli. 1.