Statut  Confirmé 
Série  SEMDARBOUX 
Domaines  condmat,hepth,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] univlyon1 [dot] fr 
Institution de l'orateur  Institut Camille Jordan, Université Claude Bernard Lyon 1 
Titre  The noncommutative topological approach to topological phases with protecting symmetry 
Résumé  In this talk we review the Ktheoretic 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 welldefined, 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 Ktheory and its dual (Khomology 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) 
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