13
votes
3answers
1k views
Noncommutative smooth manifolds
Connes defined a noncommutative analog of a closed oriented Riemannian spin^c manifold using spectral triples.
Using his definition it is unclear how to separate the smooth struct …
9
votes
5answers
1k views
Non-commutative geometry from von Neumann algebras?
The Gelfand transform gives an equivalence of categories from the category of unital, commutative $C^*$-algebras with unital $*$-homomorphisms to the category of compact Hausdorff …
9
votes
0answers
430 views
Can we define spectral triples using the language of rigged Hilbert spaces?
The traditional mathematical approach to quantum mechanics,
as developed by von Neumann, is based on Hilbert spaces and unbounded self-adjoint operators.
Another approach, which mo …
3
votes
1answer
234 views
Manifolds whose isometry group is Pati-Salam?
By the Pati-Salam group I refer to SU(2) x SU(2) x SU(4). It can be obtained as the group of isometries of the 8 dimensional manifold $S^3 \times S^5$, but I wonder if this is the …
3
votes
0answers
211 views
Obstructions to existence of finitely summable spectral triples
Connes proved in his beautiful paper "Compact metric spaces, Fredholm modules, and hyperfiniteness" published in 1989 that if $(A,H,D)$ is a finitely summable spectral triple with …

