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A polynomial version of Cereceda's conjecture

Published: 01 July 2022 Publication History

Abstract

Let k and d be positive integers such that k ≥ d + 2. Consider two k-colourings of a d-degenerate graph G. Can we transform one into the other by recolouring one vertex at each step while maintaining a proper colouring at any step? Cereceda et al. answered that question in the affirmative, and exhibited a recolouring sequence of exponential length. However, Cereceda conjectured that there should exist one of quadratic length.
The k-reconfiguration graph of G is the graph whose vertices are the proper k-colourings of G, with an edge between two colourings if they differ on exactly one vertex. Cereceda's conjecture can be reformulated as follows: the diameter of the ( d + 2 )-reconfiguration graph of any d-degenerate graph on n vertices is O ( n 2 ). So far, there is no proof of a polynomial upper bound on the diameter, even for d = 2.
In this paper, we prove that the diameter of the k-reconfiguration graph of a d-degenerate graph is O ( n d + 1 ) for k ≥ d + 2. Moreover, we prove that if k ≥ 3 2 ( d + 1 ) then the diameter of the k-reconfiguration graph is quadratic, improving the previous bound of k ≥ 2 d + 1. We also show that the 5-reconfiguration graph of planar bipartite graphs has quadratic diameter, confirming Cereceda's conjecture for this class of graphs.

References

[1]
H.-J. Böckenhauer, E. Burjons, M. Raszyk, P. Rossmanith, Reoptimization of parameterized problems, arXiv e-prints, 2018.
[2]
M. Bonamy, N. Bousquet, Recoloring graphs via tree decompositions, Eur. J. Comb. 69 (2018) 200–213.
[3]
M. Bonamy, N. Bousquet, C. Feghali, M. Johnson, On a conjecture of Mohar concerning Kempe equivalence of regular graphs, J. Comb. Theory, Ser. B 135 (2019) 179–199.
[4]
M. Bonamy, N. Bousquet, G. Perarnau, Frozen ( Δ + 1 )-colourings of bounded degree graphs, Comb. Probab. Comput. 30 (3) (2021) 330–343.
[5]
M. Bonamy, M. Johnson, I. Lignos, V. Patel, D. Paulusma, Reconfiguration graphs for vertex colourings of chordal and chordal bipartite graphs, J. Comb. Optim. (2012) 1–12.
[6]
P. Bonsma, L. Cereceda, Finding paths between graph colourings: PSPACE-completeness and superpolynomial distances, Theor. Comput. Sci. 410 (50) (2009) 5215–5226.
[7]
P. Bose, A. Lubiw, V. Pathak, S. Verdonschot, Flipping edge-labelled triangulations, Comput. Geom. 68 (2018) 309–326.
[8]
N. Bousquet, G. Perarnau, Fast recoloring of sparse graphs, Eur. J. Comb. 52 (2016) 1–11.
[9]
L. Cereceda, Mixing Graph Colourings, PhD thesis London School of Economics and Political Science, 2007.
[10]
L. Cereceda, J. van den Heuvel, M. Johnson, Mixing 3-colourings in bipartite graphs, Eur. J. Comb. 30 (7) (2009) 1593–1606.
[11]
L. Cereceda, J. van den Heuvel, M. Johnson, Finding paths between 3-colorings, J. Graph Theory 67 (1) (2011) 69–82.
[12]
S. Chen, M. Delcourt, A. Moitra, G. Perarnau, L. Postle, Improved bounds for randomly sampling colorings via linear programming, in: Proceedings of the Thirtieth Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2019, 2019, pp. 2216–2234.
[13]
R. Diestel, Graph Theory, Graduate Texts in Mathematics, vol. 173, third edition, Springer-Verlag, Heidelberg, 2005.
[14]
M. Dyer, A.D. Flaxman, A.M. Frieze, E. Vigoda, Randomly coloring sparse random graphs with fewer colors than the maximum degree, Random Struct. Algorithms 29 (4) (2006) 450–465.
[15]
E. Eiben, C. Feghali, Toward cereceda's conjecture for planar graphs, J. Graph Theory (2019).
[16]
C. Feghali, Paths between colourings of sparse graphs, Eur. J. Comb. 75 (2019) 169–171.
[17]
C. Feghali, Reconfiguring 10-colourings of planar graphs, arXiv e-prints, 2019.
[18]
C. Feghali, M. Johnson, D. Paulusma, A reconfigurations analogue of Brooks' theorem and its consequences, J. Graph Theory 83 (4) (2016) 340–358.
[19]
A. Frieze, E. Vigoda, A survey on the use of Markov chains to randomly sample colourings, Oxf. Lect. Ser. Math. Appl. 34 (2007) 53.
[20]
B. Mohar, J. Salas, On the non-ergodicity of the Swendsen–Wang–Kotecký algorithm on the Kagomé lattice, J. Stat. Mech. Theory Exp. 2010 (05) (2010).
[21]
N. Nishimura, Introduction to reconfiguration, Algorithms 11 (4) (2018) 52.
[22]
J. van den Heuvel, The complexity of change, p. 409 in: S.R. Blackburn, S. Gerke, M. Wildon (Eds.), Part of London Mathematical Society Lecture Note Series, 2013.

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  • (2024)Optimally reconfiguring list and correspondence colouringsEuropean Journal of Combinatorics10.1016/j.ejc.2023.103798115:COnline publication date: 1-Jan-2024

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        Published In

        cover image Journal of Combinatorial Theory Series B
        Journal of Combinatorial Theory Series B  Volume 155, Issue C
        Jul 2022
        389 pages

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        Academic Press, Inc.

        United States

        Publication History

        Published: 01 July 2022

        Author Tags

        1. Reconfiguration
        2. Coloring
        3. Cereceda's conjecture
        4. Degenerate graphs

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        • (2024)Optimally reconfiguring list and correspondence colouringsEuropean Journal of Combinatorics10.1016/j.ejc.2023.103798115:COnline publication date: 1-Jan-2024

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