Barát–Thomassen conjecture

Bondy–Murty, Graph Theory, Appendix A, item 11 · Covers, decompositions and packings

Bondy–Murty Conjecture — first stated 2006

Status solved high confidence

The Barát–Thomassen conjecture was proved in full by Bensmail, Harutyunyan, Le, Merker, and Thomassé (2017). They showed that for every tree T on m edges there exists a constant k_T such that every k_T-edge-connected graph whose number of edges is divisible by m can be edge-decomposed into copies of T, confirming exactly the statement as given. The paper appeared in Journal of Combinatorial Theory, Series B, volume 124 (2017), following an arXiv preprint from March 2016.

Cited literature (2)

Reviewer notes. The conjecture is fully resolved. The proof (arXiv:1603.00197, JCTB 124, 2017) directly matches the statement as given in Bondy–Murty: for every tree T there exists k(T) such that every simple k(T)-edge-connected graph with |E(G)| divisible by e(T) decomposes into copies of T. The DOI 10.1016/j.jctb.2016.12.006 is taken from the book's editorial note; the redirect to linkinghub.elsevier.com/pii/S0095895616301137 was confirmed but content not retrieved. The related corpus record arXiv:1507.08208 (Bensmail–Harutyunyan–Le–Thomassé, 2015) handled only the path case and proposed a refinement of the conjecture; it is strictly weaker than the settled full result.

Auto-reviewed 2026-09-10 with claude-sonnet-4-6 (web search enabled).

Conjecture. For every tree $T$ there exists a natural number $k := k(T)$ such that every simple $k$-edge-connected graph whose number of edges is divisible by $e(T)$ admits a decomposition into copies of $T$.

In the book: Exercise 2.4.8, Exercise 17.4.19.

Related records in this index

This conjecture was absent from the Open Problem Garden and arXiv corpora; the records below are the nearest ones.

Editorial notes. Editorial lead, to be confirmed by the status review: Bensmail, Harutyunyan, Le, Merker and Thomassé, 'A proof of the Barát–Thomassen conjecture', J. Combin. Theory Ser. B 124 (2017).

Source

Théorie des graphes (J.A. Bondy, U.S.R. Murty; French edition by Frédéric Havet, 2025), Appendix A « Problèmes ouverts »
Item 11, book p. 627 (PDF p. 643) · https://inria.hal.science/hal-05211979v1 · PDF
English edition: J.A. Bondy, U.S.R. Murty, Graph Theory, GTM 244, Springer 2008, Appendix A.