"Spherical
Tuples of Hilbert Space Operators"
By
SAMEER CHAVAN
(Indian Institute of
Technology, Kanpur)
Abstract: We discuss a class of operator
tuples in complex Hilbert spaces, which we call spherical tuples. In
particular, we characterize spherical multi-shifts, and more generally, multiplication
tuples on reproducing kernel Hilbert spaces. We further use these
characterizations to describe various spectral parts including the Taylor
spectrum. We also find a criterion for the Schatten $S_p$-class membership of cross-commutators
of spherical $m$-shifts. We show, in particular, that cross-commutators of
non-compact spherical $m$-shifts cannot belong to $S_p$ for $p \le m$. This is
a joint work with Dmitry Yakubovich.
Date: Wednesday, July 1, 2015
Time: 15:40
Place: Mathematics Seminar Room, SA-141
Tea and cookies will be served before the
seminar.