To appear with unknown date
- Hamiltonian cycles in subdivided doubles.
D. Eppstein.
arXiv:2510.18359.
Ars Mathematica Contemporanea, to appear.
The subdivided double construction turns a 4-regular graph into a bigger 4-regular graph, by subdividing each edge and doubling each vertex. We prove that the resulting graphs, which include the Folkman graph, have the following curious property: every Hamiltonian cycle (of which there are exponentially many) is complementary to another Hamiltonian cycle.