Daniel Stevenson, UCR Title: `Cyclic homology and the twisted Chern character' Abstract: The twisted K-theory of a manifold M is defined as vertical homotopy classes of sections of a bundle with fibre the Fredholm operators of some complex Hilbert space or alternatively as the K-theory of the C^*-algebra of sections of a bundle of infinite dimensional matrix algebras over M. One difference from ordinary K-theory is that the target space of the Chern character is a `twisted' version of de Rham cohomology. We give a construction of this Chern character in the spirit of non-commutative geometry by identifying the periodic cyclic homology of a smooth sub-algebra of the C^* algebra with twisted de Rham cohomology. This is joint work with Mathai Varghese from University of Adelaide.