| Statut | Confirmé | 
                      | Série | SEM-DARBOUX | 
                      | Domaines | cond-mat,hep-th,math.MP | 
                      | Date | Jeudi 4 Fevrier 2021 | 
                      | Heure | 11:00 | 
                      | Institut | LPTHE | 
                      | Salle | Zoom | 
                      | Nom de l'orateur | Kellendonk | 
                      | Prenom de l'orateur | Johannes | 
                      | Addresse email de l'orateur | kellendonk [at] math [dot] univ-lyon1 [dot] fr | 
                      | Institution de l'orateur | Institut Camille Jordan, Université Claude Bernard Lyon 1 | 
                      | Titre | The non-commutative topological approach to topological phases with protecting symmetry | 
                      | Résumé | In this talk we review the K-theoretic description of topological phases of 
insulators and superconductors in the effective one particle approximation. In 
that approximation, an insulator (or superconductor) is described by a Hamiltonian 
whose spectrum has a gap at the Fermi energy. Two Hamiltonians belong to the same 
topological phase if they can be deformed into each other without closing the gap. 
For this to be well-defined, it is important to specify the space of possible 
Hamiltonians with its topology. When this space is taken to be a C*-algebra 
equipped with a real structure and a grading, one can use real graded K-theory and 
its dual (K-homology or cyclic cohomology) to describe the topological phases and 
their numerical topological invariants. | 
                      | Numéro de preprint arXiv |  | 
                      | Commentaires | Identifiant Zoom: 968 7367 5661 (Code:958244) | 
                      | Fichiers attachés |  Paris2021.pdf (213998 bytes)
 
 |