On interrelations between graph complexes

We study Maxim Kontsevich's graph complex $GC_d$ for any integer $d$ as well as its oriented and targeted versions, and show new short proofs of the theorems due to Thomas Willwacher and Marko Zivkovic which establish isomorphisms of their cohomology groups. A new result relating the cohomology of the sourced-targeted graph complex in dimension $d+1$ with the direct sum of two copies of the cohomology group of Maxim Kontsevich's graph complex $GC_d$ in dimension $d$ is obtained. We introduce a new graph complex spanned by purely trivalent graphs and show that its cohomology is isomorphic to $H(GC_d)$.