Abstract
The universal cover T G of a connected graph G is the unique (possibly infinite) tree covering G, i.e., that allows a locally bijective homomorphism from T G to G. It is well-known that if a graph G covers a graph H, then their universal covers are isomorphic, and that the latter can be tested in polynomial time by checking if G and H share the same degree refinement matrix. We extend this result to locally injective and locally surjective homomorphisms by following a very different approach. Using linear programming techniques we design two polynomial time algorithms that check if there exists a locally injective or a locally surjective homomorphism, respectively, from a universal cover T G to a universal cover T H (both given by their degree matrices). This way we obtain two heuristics for testing the corresponding locally constrained graph homomorphisms. Our algorithm can also be used for testing (subgraph) isomorphism between universal covers, and for checking if there exists a locally injective or locally surjective homomorphism (role assignment) from a given tree to an arbitrary graph H.
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Abello, J., Fellows, M.R., Stillwell, J.C.: On the complexity and combinatorics of covering finite complexes. Aust. J. Comb. 4, 103–112 (1991)
Angluin, D.: Local and global properties in networks of processors. In: Proceedings of the 12th ACM Symposium on Theory of Computing, pp. 82–93 (1980)
Angluin, D., Gardiner, A.: Finite common coverings of pairs of regular graphs. J. Comb. Theory B 30, 184–187 (1981)
Biggs, N.: Algebraic Graph Theory. Cambridge University Press, Cambridge (1974)
Biggs, N.: Constructing 5-arc transitive cubic graphs. J. Lond. Math. Soc. II 26, 193–200 (1982)
Bodlaender, H.L.: The classification of coverings of processor networks. J. Parallel Distrib. Comput. 6, 166–182 (1989)
Bodlaender, H.L.: A tourist guide through treewidth. Acta Cybern. 11(1–2), 1–22 (1993)
Bondy, J.A., Murty, U.S.R.: Graph Theory with Applications. American Elsevier, New York (1976)
Chalopin, J., Métivier, Y., Zielonka, W.: Local computations in graphs: the case of cellular edge local computations. Fundam. Inform. 74(1), 85–114 (2006)
Dantchev, S., Martin, B.D., Stewart, I.A.: On non-definability of unsatisfiability. Manuscript
Edmonds, J., Karp, R.M.: Theoretical improvements in algorithmic efficiency for network flow problems. J. ACM 19, 248–264 (1972)
Everett, M.G., Borgatti, S.: Role colouring a graph. Math. Soc. Sci. 21(2), 183–188 (1991)
Fiala, J., Kratochvíl, J.: Complexity of partial covers of graphs. In: Eades, P., Takaoka, T. (eds.) ISAAC. Lecture Notes in Computer Science, vol. 2223, pp. 537–549. Springer, New York (2001)
Fiala, J., Kratochvíl, J.: Partial covers of graphs. Discuss. Math. Graph Theory 22, 89–99 (2002)
Fiala, J., Maxová, J.: Cantor-Bernstein type theorem for locally constrained graph homomorphisms. Eur. J. Comb. 7(27), 1111–1116 (2006)
Fiala, J., Paulusma, D.: A complete complexity classification of the role assignment problem. Theor. Comput. Sci. 1(349), 67–81 (2005)
Fiala, J., Paulusma, D.: Comparing universal covers in polynomial time. In: Hirsch, E.A., Razborov, A.A., Semenov, A.L., Slissenko, A. (eds.) CSR. Lecture Notes in Computer Science, vol. 5010, pp. 158–167. Springer, Berlin (2008)
Fiala, J., Kratochvíl, J., Kloks, T.: Fixed-parameter complexity of λ-labelings. Discrete Appl. Math. 113(1), 59–72 (2001)
Fiala, J., Heggernes, P., Kristiansen, P., Telle, J.A.: Generalized H-coloring and H-covering of trees. Nord. J. Comput. 10(3), 206–224 (2003)
Fiala, J., Golovach, P.A., Kratochvíl, J.: Distance constrained labelings of graphs of bounded treewidth. In: Caires, L., Italiano, G.F., Monteiro, L., Palamidessi, C., Yung, M. (eds.) ICALP. Lecture Notes in Computer Science, vol. 3580, pp. 360–372. Springer, New York (2005)
Fiala, J., Paulusma, D., Telle, J.A.: Locally constrained graph homomorphism and equitable partitions. Eur. J. Comb. 29(4), 850–880 (2008)
Godsil, C.D.: Algebraic Combinatorics. Chapman and Hall, New York (1993)
Hell, P., Nešetřil, J.: Graphs and Homomorphisms. Oxford University Press, Oxford (2004)
Hoffman, A.J., Kruskal, J.G.: Integral boundary points of convex polyhedra. Ann. Math. Stud. 38, 223–246 (1956)
Kranakis, E., Krizanc, D., van den Berg, J.: Computing Boolean functions on anonymous networks. Inf. Comput. 114(2), 214–236 (1994)
Kratochvíl, J., Proskurowski, A., Telle, J.A.: Covering directed multigraphs I. Colored directed multigraphs. In: Möhring, R.H. (ed.) WG. Lecture Notes in Computer Science, vol. 1335, pp. 242–257. Springer, Berlin (1997)
Kratochvíl, J., Proskurowski, A., Telle, J.A.: Covering regular graphs. J. Comb. Theory, Ser. B 71(1), 1–16 (1997)
Kristiansen, P., Telle, J.A.: Generalized H-coloring of graphs. In: Lee, D.T., Teng, S.-H. (eds.) ISAAC. Lecture Notes in Computer Science, vol. 1969, pp. 456–466. Springer, Berlin (2000)
Leighton, F.T.: Finite common coverings of graphs. J. Comb. Theory B 33, 231–238 (1982)
Massey, W.S.: Algebraic Topology: An Introduction. Harcourt, Brace and World, New York (1967)
Moore, E.F.: Gedanken-experiments on sequential machines. In: Automata Studies. Annals of Mathematics Studies, vol. 34, pp. 129–153. Princeton University Press, Princeton (1956)
Nešetřil, J.: Homomorphisms of derivative graphs. Discrete Math. 1(3), 257–268 (1971)
Norris, N.: Universal covers of graphs: isomorphism to depth n−1 implies isomorphism to all depths. Discrete Appl. Math. 56(1), 61–74 (1995)
Pekeč, A., Roberts, F.S.: The role assignment model nearly fits most social networks. Math. Soc. Sci. 41(3), 275–293 (2001)
Reidemeister, K.: Einführung in die kombinatorische Topologie. Braunschweig: Friedr. Vieweg & Sohn A.-G. XII, 209 S. (1932)
Roberts, F.S., Sheng, L.: How hard is it to determine if a graph has a 2-role assignment? Networks 37(2), 67–73 (2001)
Schwenk, A.J.: Computing the characteristic polynomial of a graph. In: Graphs and Combinatorics. Lecture Notes in Mathematics, vol. 406, pp. 153–172. Springer, Berlin (1974)
Shamir, R., Tsur, D.: Faster subtree isomorphism. J. Algorithms 33(2), 267–280 (1999)
Yamashita, M., Kameda, T.: Computing on anonymous networks: Part I—characterizing the solvable cases. IEEE Trans. Parallel Distrib. Syst. 7(1), 69–89 (1996)
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A preliminary version of this article has been published in proceedings of the 3rd International Computer Science Symposium in Russia [17].
ITI supported by the Ministry of Education of the Czech Republic as project 1M0021620808.
D. Paulusma supported by EPSRC as project EP/D053633/1.
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Fiala, J., Paulusma, D. Comparing Universal Covers in Polynomial Time. Theory Comput Syst 46, 620–635 (2010). https://doi.org/10.1007/s00224-009-9200-z
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DOI: https://doi.org/10.1007/s00224-009-9200-z