Petruševski–Škrekovski edge-deletion conjecture for odd edge-colorings

Let GG be a connected graph that is not a Shannon triangle of type (2,2,2)(2,2,2) or type (2,2,1)(2,2,1). Write χodd(G)\chi_{\text{odd}}'(G) for the odd chromatic index, and call an edge special if its removal makes the graph odd 33-edge-colorable. Petruševski–Škrekovski edge-deletion conjecture. Either

χodd(G)3,\chi_{\text{odd}}'(G)\leq 3,

or there exists a special edge ee whose removal makes the graph odd 33-edge-colorable. Equivalently, assuming χodd(G)=4\chi_{\text{odd}}'(G)=4, there exists an odd 44-edge-coloring in which color 44 is used only once. The paper states that this conjecture is resolved by its results; it is the edge analogue of the vertex-deletion part of the odd edge-coloring theory.

Sources & referencesView supporting material

Primary source

Xiao-Chuan Liu, Mirko Petruševski and Xu Yang, “On Graph Odd Edge-Colorings and Odd Edge-Coverings”, arXiv:2406.10192 (2025).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.