NCG and AMPQ seminar

[Emanuele Tuillier Illingworth]

Joint NCG and AMPQ Seminar

Prof. Daniele GUIDO
Universita' di Roma "Tor Vergata"

CROSSED PRODUCT OF A SPECTRAL TRIPLE WITH A SINGLE ENDOMORPHISM

The problem of extending a spectral triple from a given algebra to the
crossed product of the algebra with a single endomorphism is addressed. The
problem appears to be more complicated than the corresponding problem for
automorphisms, due to the fact that while automorphisms are often
essentially isometric, endomorphisms are rather dilations. For this reason,
the crossed product spectral triple is naturally type II semifinite.
We propose a family of examples in which the construction can be performed,
together with a new definition of crossed product of a C*-algebra with an
endomorphism. Some of these examples can be viewed as finite noncommutative
regular coverings w.r.t. an abelian group.

Thursday 29 January 2015, 2:30 P.M.
SISSA room 136