Simple cubic graphs with no short traveling salesman tour

Let $tsp(G)$ denote the length of a shortest travelling salesman tour in a graph $G$. We prove that for any $\varepsilon>0$, there exists a simple $2$-connected planar cubic graph $G_1$ such that $tsp(G_1)\ge (1.25-\varepsilon)\cdot|V(G_1)|$, a simple $2$-connected bipartite cubic graph $G_2$ such that $tsp(G_2)\ge (1.2-\varepsilon)\cdot|V(G_2)|$, and a simple $3$-connected cubic graph $G_3$ such that $tsp(G_3)\ge (1.125-\varepsilon)\cdot|V(G_3)|$

Weak oddness as an approximation of oddness and resistance in cubic graphs

We introduce weak oddness $\omega_{\textrm w}$, a new measure of uncolourability of cubic graphs, defined as the least number of odd components in an even factor. For every bridgeless cubic graph $G$, $\rho(G)\le\omega_{\textrm w}(G)\le\omega(G)$, where $\rho(G)$ denotes the resistance of $G$ and $\omega(G)$ denotes the oddness of $G$, so this new measure is an approximation of both oddness and resistance. We demonstrate that there are graphs $G$ satisfying $\rho(G) < \omega_{\textrm w}(G) < \omega(G)$, and that the difference between any two of those three measures can be arbitrarily large. The construction implies that if we replace a vertex of a cubic graph with a triangle, then its oddness can decrease by an arbitrarily large amount