AbstractWeight systems, which are functions on chord diagrams satisfying certain 4-term relations, appear naturally in Vassiliev's theory of nite type knot invariants. In particular, a weight system can be constructed from any nite dimensional Lie algebra endowed with a nondegenerate invariant bilinear form. Recently, M. Kazarian suggested to extend the gl(N)-weight system from chord diagrams (...
AbstractA Riemannian 6-manifold is called nearly Kahler if its Riemannian cone has holonomy contained in G2. Only known examples were some homogeneous spaces for a long time, but Foscolo and Haskins constructed new cohomogeneity one nearly Kahler manifolds in 2017. I will explain an outline of the construction