06.11.2024, 14:00 - 16:00
– Campus Golm, Building 9, Room 2.22 and via Zoom
Institutskolloquium
Graphon Models for Inhomogeneous Random Graphs
Olga Klopp (Paris), Nicolas Verzelen (Montpellier)
Niels Kowalzig (Università di Napoli Federico II)
In this talk, we will embed the degree -d bracket on the equivariant homology of loop spaces developed by Chas-Sullivan and Menichi on negative cyclic cohomology groups as well as the dual bracket found by de Thanhoffer de Voelcsey-Van den Bergh on negative cyclic homology groups (which are the right receptacle for the Chern character coming from algebraic K-theory) into the global picture of a noncommutative differential (or Cartan) calculus on the cyclic bicomplex in general, in case a certain Poincare' duality is given. For negative cyclic cohomology, this in particular leads to a Gerstenhaber algebra structure with generating operator, that is, a Batalin-Vilkovisky algebra structure on the underlying Hochschild cohomology. In the special case in which this BV bracket vanishes, one obtains a graded Lie bracket of degree -2 on Hochschild cohomology.
(joint work with D. Fiorenza)