$\mathfrak{sl}(2)$-weight system does not extend to a graph 4-invariant

Daniil Fomichev, Maksim Karev, Fedor Pavutnitskiy +1

A long-standing question by S. Lando asks whether the $\mathfrak{sl}(2)$-weight system extends to a unique 4-invariant of graphs. We show that, in full generality, the answer to th…