ИСТИНА

In the talk we consider chord diagrams, i.e. a circle with a set of chords. Chord diagrams are very useful in knot theory and in the theory of embedding of curves. It is well known that chord diagrams modulo 4T-relations admit a Hopf algebra structure, where the multiplication is given by a connected sum, but in the case of framed chord diagrams the situation is different. To show what happens in the case of framed chord diagrams we present invariants (modulo 4T-relations) and maps on framed chord diagrams. Also we touch the case of linear diagrams, i.e. instead of the circle we have a line.