5
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Conjecture (Csóka-Lippner-Pikhurko). If $G$ is a graph with each vertex of degree $\le d$ with at most $d-1$ pendant edges properly coloured, then this pre-colouring can be extended to all edges of $G$, using $d+1$ colours in total.

If proved, this will directly give new bounds on questions of Albert (2010) & Marks (2016) on measurable Vizing's theorem.

(This problem was written 23.08.2018 by Oleg Pikhurko on page 51 of Volume 2 of the Lviv Scottish Book).

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    $\begingroup$ I am confused. Do we colour edges or vertices? What are pending edges? $\endgroup$ – Fedor Petrov Oct 22 '18 at 23:05
  • $\begingroup$ @FedorPetrov If I understood the problem correctly, we colour edges and pending edges are edges that contain a vertex of degree 1. But I will contact Oleg Pikhurko and will ask him to comment on this. $\endgroup$ – Lviv Scottish Book Oct 23 '18 at 9:16
  • $\begingroup$ Still unclear. What are restrictions on the graph and what is already coloured? $\endgroup$ – Fedor Petrov Oct 23 '18 at 9:54
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    $\begingroup$ @FedorPetrov I added the link (just after "Conjecture") to the original paper of Csoka-Lippner-Pikhurko (doi.org/10.1017/fms.2016.22). This conjecture is Conjecture 1.7. Definition 1.6 explains the terminology. $\endgroup$ – Lviv Scottish Book Oct 23 '18 at 10:01

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