Nico Spronk, Department of Pure Mathematics, University of Waterloo
"On the subalgebra of a Fourier-Stieltjes algebra generated by pure positive definite functions"
Abstract:
For
a
locally
compact
group
$G$,
Yin-Hei
Cheng
considered
the
closed
subspace
$a_0(G)$
which
is
generated
by
the
pure
positive
definite
functions.
In
many
cases
$a_0(G)$
is
itself
an
algebra.
We
illustrate
using
Heisenberg
groups
and
the
$2\times
2$
real
special
linear
group,
that
this
is
not
the
case
in
general.
We
examine
the
structures
of
the
algebras
thereby
created
and
examine
properties
related
to
amenability.
This
is
joint
work
with
Yin-Hei
Cheng
and
Brian
Forrest.