Vitayard OCT.2013 | Page 10

http://vitayard.in Open Science and Research Project OKFN, India Dirac operators on noncommutative curved spacetimes Alexander Schenkel, Christoph F. Uhlemann Description: We study Dirac operators in the framework of twist-deformed noncommutative geometry. The definition of noncommutative Dirac operators is not unique and we focus on three different ones, each generalizing the commutative Dirac operator in a natural way. We show that the three definitions are mutually inequivalent, and that demanding formal self-adjointness with respect to a suitable inner product singles out a preferred choice. A detailed analysis shows that, if the Drinfeld twist contains sufficiently many Killing vector fields, the three operators coincide, which can simplify explicit calculations considerably. We then turn to the construction of quantized Dirac fields on noncommutative curved spacetimes. We show that there exist unique retarded and advanced Green’s operators and construct a canonical anti-commutation relation algebra. In the last part we study noncommutative Minkowski and AdS spacetimes as explicit examples. Cite as: arXiv:1308.1929 [hep-th] (or arXiv:1308.1929v1 [hep-th] for this version) Read full version at : Paper 10