AbstractWe discuss the notions of path homology and homotopy of digraphs. The following topic will bepresented.. Homology groups of digraphs.. Homotopy of digraph maps and digraphs. lnvariance of homology groups under homotopy.Fundamental group of a digraph. Invariance of the fundamental group under homotopy.Relation between the fundamental group and first homology group.Speaker IntroProfessor ...
AbstractIn the marriage of low dimensional topology and symplectic topology, there lives Legendrians knots and their exact Lagrangian fillings. Legendrian knots are smooth knots satisfying some tangency conditions, such that their projection diagrams have certain cusps. The Lagrangian fillings are filling surfaces of knots in the 4-dimensional ball, again satisfying some extra conditions. Legen...