# Extensions and degeneration of spectral triples

Erik Christensen
(Copenhagen)
Analyseseminar
Onsdag, 3 oktober, 2012, at 13:15-14:00, in Aud. G1 (1532-116)
Abstrakt:
Given an unital C*-algebra E, which is an extension of a unital C*-algebra A by the compacts. We investigate various ways in which a spectral triple for A induce a spectral triple for E, and based on this we construct a 2-parameter family of such spectral triples on E and show that the compact quantum metric spaces associated to E will converge in the Gromow-Hausdorff metric to given the compact quantum metric space on A, when one of the parameters decrease to 0. This is analogous to the setup of the metric s*d_X+t*d_Y on a product of two classical metric spaces (X,d_X) and (Y,d_Y) when s=1 and t goes to 0. (Joint work with Christina Ivan, M.D. Anderson Cancer Center, Houston, Texas.)
Kontaktperson: Klaus Thomsen