Covariant star product on semi-conformally flat noncommutative Calabi–Yau manifolds and noncommutative topological index theorem
Abstract
A differential geometric statement of the noncommutative topological index theorem is worked out for covariant star products on noncommutative vector bundles. To start, a noncommutative manifold is considered as a product space , wherein is a closed manifold, and is a flat Calabi–Yau -fold. Also, a semi-conformally flat metric is considered for which leads to a dynamical noncommutative spacetime from the viewpoint of noncommutative gravity. Based on the Kahler form of the noncommutative star product is defined covariantly on vector bundles over . This covariant star product leads to the celebrated Groenewold–Moyal product for trivial vector bundles and their flat connections, such as . Hereby, the noncommutative characteristic classes are defined properly and the noncommutative Chern–Weil theory is established by considering the covariant star product and the superconnection formalism. Finally, the index of the ⋆-noncommutative version of elliptic operators is studied and the noncommutative topological index theorem is stated accordingly.