Mathematics – Quantum Algebra
Scientific paper
2000-11-23
Mathematics
Quantum Algebra
67 pages
Scientific paper
We describe basic concepts of noncommutative geometry and a general construction extending the familiar duality between ordinary spaces and commutative algebras to a duality between Quotient spaces and Noncommutative algebras. Basic tools of the theory, K-theory, Cyclic cohomology, Morita equivalence, Operator theoretic index theorems, Hopf algebra symmetry are reviewed. They cover the global aspects of noncommutative spaces, such as the transformation $\theta \to 1/\theta$ for the NC torus $\Tb_{\theta}^2$, unseen in perturbative expansions in $\theta$ such as star or Moyal products. We discuss the foundational problem of "what is a manifold in NCG" and explain the role of Poincare duality in K-homology which is the basic reason for the spectral point of view. When specializing to 4-geometries this leads to the universal "Instanton algebra". We describe our work with G. Landi which gives NC-spheres $S_{\theta}^4$ from representations of the Instanton algebra. We show that any compact Riemannian spin manifold whose isometry group has rank $r \geq 2$ admits isospectral deformations to noncommutative geometries. We give a survey of our work with H. Moscovici on the transverse geometry of foliations which yields a diffeomorphism invariant geometry on the bundle of metrics on a manifold and a natural extension of cyclic cohomology to Hopf algebras. Then, our work with D. Kreimer on renormalization and the Riemann-Hilbert problem. Finally we describe the spectral realization of zeros of zeta and L-functions from the noncommutative space of Adele classes on a global field and its relation with the Arthur-Selberg trace formula in the Langlands program. We end with a tentalizing connection between the renormalization group and the missing Galois theory at Archimedian places.
No associations
LandOfFree
Noncommutative Geometry Year 2000 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Noncommutative Geometry Year 2000, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Noncommutative Geometry Year 2000 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-729585