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As Time Goes By: Reflections on Treewidth for Temporal Graphs

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Treewidth, Kernels, and Algorithms

Abstract

Treewidth is arguably the most important structural graph parameter leading to algorithmically beneficial graph decompositions. Triggered by a strongly growing interest in temporal networks (graphs where edge sets change over time), we discuss fresh algorithmic views on temporal tree decompositions and temporal treewidth. We review and explain some of the recent work together with some encountered pitfalls, and we point out challenges for future research.

Dedicated to Hans L. Bodlaender on the occasion of his 60th birthday.

The inclined reader, besides hopefully discovering interesting science, is also invited to enjoy a few quotes from a famous movie scattered around our text; the paper title is partially taken from the theme song of this movie.

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Notes

  1. 1.

    Also known as time-varying graphs, evolving graphs, link streams, or dynamic graphs where no changes on the vertex set are allowed.

  2. 2.

    In the Gaifman graph of a structure, there is one vertex for each element in the universe and two vertices have an edge if and only if the corresponding elements occur together in the same relation.

  3. 3.

    A \(\varDelta \)-time window is a set of \(\varDelta \) consecutive time steps.

  4. 4.

    To the best of our knowledge, the concept of a “\(\varDelta \)-slice parameter” was introduced by Himmel et al. [51] to define a temporal version of degeneracy. It was later also used by Bentert et al. [7].

  5. 5.

    Note that there are different definitions of static expansion that are typically tailored to the applications they are used in.

References

  1. Abraham, I., Chechik, S., Delling, D., Goldberg, A.V., Werneck, R.F.: On dynamic approximate shortest paths for planar graphs with worst-case costs. In: Proceedings of the 27th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2016), pp. 740–753. SIAM (2016)

    Google Scholar 

  2. Akrida, E.C., Mertzios, G.B., Spirakis, P.G.: The temporal explorer who returns to the base. In: Heggernes, P. (ed.) CIAC 2019. LNCS, vol. 11485, pp. 13–24. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-17402-6_2

    Chapter  Google Scholar 

  3. Akrida, E.C., Mertzios, G.B., Spirakis, P.G., Zamaraev, V.: Temporal vertex cover with a sliding time window. J. Comput. Syst. Sci. 107, 108–123 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  4. Arnborg, S., Corneil, D.G., Proskurowski, A.: Complexity of finding embeddings in a \(k\)-tree. SIAM J. Algebraic Discrete Methods 8(2), 277–284 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  5. Arnborg, S., Lagergren, J., Seese, D.: Easy problems for tree-decomposable graphs. J. Algorithms 12(2), 308–340 (1991)

    Article  MathSciNet  MATH  Google Scholar 

  6. Axiotis, K., Fotakis, D.: On the size and the approximability of minimum temporally connected subgraphs. In: Proceedings of the 43rd International Colloquium on Automata, Languages, and Programming (ICALP 2016). LIPIcs, vol. 55, pp. 149:1–149:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2016)

    Google Scholar 

  7. Bentert, M., Himmel, A.S., Molter, H., Morik, M., Niedermeier, R., Saitenmacher, R.: Listing all maximal \(k\)-plexes in temporal graphs. ACM J. Exp. Algorithmics 24(1), 1–13 (2019)

    Article  MathSciNet  Google Scholar 

  8. Betzler, N., Bredereck, R., Niedermeier, R., Uhlmann, J.: On bounded-degree vertex deletion parameterized by treewidth. Discrete Appl. Math. 160(1–2), 53–60 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  9. Bodlaender, H.L.: Dynamic algorithms for graphs with treewidth 2. In: van Leeuwen, J. (ed.) WG 1993. LNCS, vol. 790, pp. 112–124. Springer, Heidelberg (1994). https://doi.org/10.1007/3-540-57899-4_45

    Chapter  Google Scholar 

  10. Bodlaender, H.L.: A tourist guide through treewidth. Acta Cybernetica 11(1–2), 1–21 (1993)

    MathSciNet  MATH  Google Scholar 

  11. Bodlaender, H.L.: A linear-time algorithm for finding tree-decompositions of small treewidth. SIAM J. Comput. 25(6), 1305–1317 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  12. Bodlaender, H.L.: The algorithmic theory of treewidth. Electron. Notes Discrete Math. 5, 27–30 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  13. Bodlaender, H.L., Drange, P.G., Dregi, M.S., Fomin, F.V., Lokshtanov, D., Pilipczuk, M.: A \(c^k n\) 5-approximation algorithm for treewidth. SIAM J. Comput. 45(2), 317–378 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  14. Bodlaender, H.L., Hagerup, T.: Parallel algorithms with optimal speedup for bounded treewidth. SIAM J. Comput. 27(6), 1725–1746 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  15. Bodlaender, H.L., Kloks, T.: Efficient and constructive algorithms for the pathwidth and treewidth of graphs. J. Algorithms 21(2), 358–402 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  16. Bodlaender, H.L., Kloks, T., Kratsch, D.: Treewidth and pathwidth of permutation graphs. SIAM J. Discrete Math. 8(4), 606–616 (1995)

    Article  MathSciNet  MATH  Google Scholar 

  17. Bodlaender, H.L., Kloks, T., Kratsch, D., Müller, H.: Treewidth and minimum fill-in on \(d\)-trapezoid graphs. J. Graph Algorithms Appl. 2(5), 1–23 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  18. Bodlaender, H.L., Koster, A.M.C.A.: Treewidth computations II. Lower bounds. Inf. Comput. 209(7), 1103–1119 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  19. Bodlaender, H.L., Möhring, R.H.: The pathwidth and treewidth of cographs. SIAM J. Discrete Math. 6(2), 181–188 (1993)

    Article  MathSciNet  MATH  Google Scholar 

  20. Bodlaender, H.L., Thilikos, D.M.: Treewidth for graphs with small chordality. Discrete Appl. Math. 79(1–3), 45–61 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  21. Bodlaender, H.L., van der Zanden, T.C.: On exploring always-connected temporal graphs of small pathwidth. Inf. Process. Lett. 142, 68–71 (2019)

    Article  MathSciNet  MATH  Google Scholar 

  22. Bouchitté, V., Todinca, I.: Treewidth and minimum fill-in: grouping the minimal separators. SIAM J. Comput. 31(1), 212–232 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  23. Casteigts, A., Flocchini, P., Quattrociocchi, W., Santoro, N.: Time-varying graphs and dynamic networks. Int. J. Parallel Emergent Distrib. Syst. 27(5), 387–408 (2012)

    Article  Google Scholar 

  24. Casteigts, A., Himmel, A.S., Molter, H., Zschoche, P.: The computational complexity of finding temporal paths under waiting time constraints. CoRR abs/1909.06437 (2019)

    Google Scholar 

  25. Casteigts, A., Peters, J.G., Schoeters, J.: Temporal cliques admit sparse spanners. In: Proceedings of the 46th International Colloquium on Automata, Languages, and Programming (ICALP 2019). LIPIcs, vol. 132, pp. 134:1–134:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2019)

    Google Scholar 

  26. Courcelle, B., Engelfriet, J.: Graph Structure and Monadic Second-Order Logic: A Language-Theoretic Approach. Cambridge University Press, Cambridge (2012)

    Book  MATH  Google Scholar 

  27. Cygan, M., et al.: Parameterized Algorithms. Springer, Heidelberg (2015). https://doi.org/10.1007/978-3-319-21275-3

    Book  MATH  Google Scholar 

  28. Dailey, D.P.: Uniqueness of colorability and colorability of planar 4-regular graphs are NP-complete. Discrete Math. 30(3), 289–293 (1980)

    Article  MathSciNet  MATH  Google Scholar 

  29. Deligkas, A., Potapov, I.: Optimizing reachability sets in temporal graphs by delaying. In: Proceedings of the 34th AAAI Conference on Artificial Intelligence (AAAI 2020). AAAI Press (2020, to appear)

    Google Scholar 

  30. Dell, H., Husfeldt, T., Jansen, B.M.P., Kaski, P., Komusiewicz, C., Rosamond, F.A.: The first parameterized algorithms and computational experiments challenge. In: Proceedings of the 11th International Symposium on Parameterized and Exact Computation (IPEC 2016). LIPIcs, vol. 63, pp. 30:1–30:9. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2016)

    Google Scholar 

  31. Dell, H., Komusiewicz, C., Talmon, N., Weller, M.: The PACE 2017 parameterized algorithms and computational experiments challenge: the second iteration. In: Proceedings of the 12th International Symposium on Parameterized and Exact Computation (IPEC 2017). LIPIcs, vol. 89, pp. 30:1–30:12. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2017)

    Google Scholar 

  32. Dom, M., Lokshtanov, D., Saurabh, S., Villanger, Y.: Capacitated domination and covering: a parameterized perspective. In: Grohe, M., Niedermeier, R. (eds.) IWPEC 2008. LNCS, vol. 5018, pp. 78–90. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-79723-4_9

    Chapter  MATH  Google Scholar 

  33. Downey, R.G., Fellows, M.R.: Parameterized Complexity. Monographs in Computer Science. Springer, Heidelberg (1999). https://doi.org/10.1007/978-1-4612-0515-9

    Book  MATH  Google Scholar 

  34. Downey, R.G., Fellows, M.R.: Fundamentals of Parameterized Complexity. Springer, London (2013). https://doi.org/10.1007/978-1-4471-5559-1

    Book  MATH  Google Scholar 

  35. Dvorák, P., Knop, D.: Parameterized complexity of length-bounded cuts and multicuts. Algorithmica 80(12), 3597–3617 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  36. Enright, J., Meeks, K., Mertzios, G., Zamaraev, V.: Deleting edges to restrict the size of an epidemic in temporal networks. In: Proceedings of the 44nd International Symposium on Mathematical Foundations of Computer Science (MFCS 2019), pp. 57:1–57:15. LIPIcs, Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2019)

    Google Scholar 

  37. Enright, J., Meeks, K., Skerman, F.: Changing times to optimise reachability in temporal graphs. CoRR abs/1802.05905 (2018)

    Google Scholar 

  38. Erlebach, T., Hoffmann, M., Kammer, F.: On temporal graph exploration. In: Halldórsson, M.M., Iwama, K., Kobayashi, N., Speckmann, B. (eds.) ICALP 2015. LNCS, vol. 9134, pp. 444–455. Springer, Heidelberg (2015). https://doi.org/10.1007/978-3-662-47672-7_36. Updated version available at https://arxiv.org/abs/1504.07976v2

    Chapter  Google Scholar 

  39. Erlebach, T., Kammer, F., Luo, K., Sajenko, A., Spooner, J.T.: Two moves per time step make a difference. In: Proceedings of the 46th International Colloquium on Automata, Languages, and Programming (ICALP 2019). LIPIcs, vol. 132, pp. 141:1–141:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2019)

    Google Scholar 

  40. Erlebach, T., Spooner, J.T.: Faster exploration of degree-bounded temporal graphs. In: Proceedings of the 43rd International Symposium on Mathematical Foundations of Computer Science (MFCS 2018). LIPIcs, vol. 117, pp. 36:1–36:13. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2018)

    Google Scholar 

  41. Erlebach, T., Spooner, J.T.: A game of cops and robbers on graphs with periodic edge-connectivity. CoRR abs/1908.06828 (2019)

    Google Scholar 

  42. Flocchini, P., Mans, B., Santoro, N.: On the exploration of time-varying networks. Theor. Comput. Sci. 469, 53–68 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  43. Flum, J., Grohe, M.: Parameterized Complexity Theory. TTCSAES, vol. XIV. Springer, Heidelberg (2006). https://doi.org/10.1007/3-540-29953-X

    Book  MATH  Google Scholar 

  44. Fluschnik, T., Kratsch, S., Niedermeier, R., Sorge, M.: The parameterized complexity of the minimum shared edges problem. J. Comput. Syst. Sci. 106, 23–48 (2019)

    Article  MathSciNet  MATH  Google Scholar 

  45. Fluschnik, T., Molter, H., Niedermeier, R., Renken, M., Zschoche, P.: Temporal graph classes: a view through temporal separators. Theor. Comput. Sci. 806, 197–218 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  46. Fluschnik, T., Niedermeier, R., Rohm, V., Zschoche, P.: Multistage vertex cover. In: Proceedings of the 14th International Symposium on Parameterized and Exact Computation (IPEC 2019). LIPIcs, vol. 148, pp. 14:1–14:14. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2019)

    Google Scholar 

  47. Froese, V., Jain, B., Niedermeier, R., Renken, M.: Comparing temporal graphs using dynamic time warping. In: Cherifi, H., Gaito, S., Mendes, J.F., Moro, E., Rocha, L.M. (eds.) COMPLEX NETWORKS 2019. SCI, vol. 882, pp. 469–480. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-36683-4_38

    Chapter  Google Scholar 

  48. Gassner, E.: The Steiner forest problem revisited. J. Discrete Algorithms 8(2), 154–163 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  49. Himmel, A.S.: Algorithmic investigations into temporal paths. Master thesis, TU Berlin, April 2018

    Google Scholar 

  50. Himmel, A.-S., Bentert, M., Nichterlein, A., Niedermeier, R.: Efficient computation of optimal temporal walks under waiting-time constraints. In: Cherifi, H., Gaito, S., Mendes, J.F., Moro, E., Rocha, L.M. (eds.) COMPLEX NETWORKS 2019. SCI, vol. 882, pp. 494–506. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-36683-4_40

    Chapter  Google Scholar 

  51. Himmel, A.S., Molter, H., Niedermeier, R., Sorge, M.: Adapting the Bron-Kerbosch algorithm for enumerating maximal cliques in temporal graphs. Soc. Netw. Anal. Min. 7(1), 35:1–35:16 (2017)

    Article  Google Scholar 

  52. Holme, P., Saramäki, J.: Temporal networks. CoRR abs/1108.1780 (2011)

    Google Scholar 

  53. Kloks, T.: Treewidth, Computations and Approximations. LNCS, vol. 842. Springer, Heidelberg (1994). https://doi.org/10.1007/BFb0045375

    Book  MATH  Google Scholar 

  54. Mans, B., Mathieson, L.: On the treewidth of dynamic graphs. Theor. Comput. Sci. 554, 217–228 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  55. Marx, D.: NP-completeness of list coloring and precoloring extension on the edges of planar graphs. J. Graph Theory 49(4), 313–324 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  56. Marx, D.: Complexity results for minimum sum edge coloring. Discrete Appl. Math. 157(5), 1034–1045 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  57. Mertzios, G.B., Molter, H., Niedermeier, R., Zamaraev, V., Zschoche, P.: Computing maximum matchings in temporal graphs. CoRR abs/1905.05304 (2019). To appear in Proceedings of the 37th International Symposium on Theoretical Aspects of Computer Science (STACS 2020), Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik. LIPIcs, vol. 154, pp. 27:1–27:14 (2020)

    Google Scholar 

  58. Mertzios, G.B., Molter, H., Zamaraev, V.: Sliding window temporal graph coloring. In: Proceedings of the 33rd AAAI Conference on Artificial Intelligence (AAAI 2019), pp. 7667–7674. AAAI Press (2019)

    Google Scholar 

  59. Misra, J., Gries, D.: A constructive proof of Vizing’s theorem. Inf. Process. Lett. 41(3), 131–133 (1992)

    Article  MathSciNet  MATH  Google Scholar 

  60. Molter, H., Niedermeier, R., Renken, M.: Enumerating isolated cliques in temporal networks. In: Cherifi, H., Gaito, S., Mendes, J.F., Moro, E., Rocha, L.M. (eds.) COMPLEX NETWORKS 2019. SCI, vol. 882, pp. 519–531. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-36683-4_42

    Chapter  Google Scholar 

  61. Niedermeier, R.: Invitation to Fixed-Parameter Algorithms. Oxford University Press, Oxford (2006)

    Book  MATH  Google Scholar 

  62. Nishizeki, T., Vygen, J., Zhou, X.: The edge-disjoint paths problem is NP-complete for series-parallel graphs. Discrete Appl. Math. 115(1–3), 177–186 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  63. Seymour, P.D., Thomas, R.: Graph searching and a min-max theorem for tree-width. J. Comb. Theory Series B 58(1), 22–33 (1993)

    Article  MathSciNet  MATH  Google Scholar 

  64. Viard, T., Latapy, M., Magnien, C.: Computing maximal cliques in link streams. Theor. Comput. Sci. 609, 245–252 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  65. Zschoche, P., Fluschnik, T., Molter, H., Niedermeier, R.: The complexity of finding small separators in temporal graphs. J. Comput. Syst. Sci. 107, 72–92 (2020)

    Article  MathSciNet  MATH  Google Scholar 

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Acknowledgments

HM and MR acknowledge support by DFG, project MATE (NI 369/17). TF acknowledges support by DFG, project TORE (NI 369/18).

We thank Mark de Berg, Anne-Sophie Himmel, Frank Kammer, Sándor Kisfaludi-Bak, Erik Jan van Leeuwen, and George B. Mertzios for their constructive feedback which helped us to improve the presentation of the paper.

We further thank Bernard Mans and Luke Mathieson for helpful discussions concerning the issues presented in Sect. 5.3.

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A Temporal Graph Problem Zoo

A Temporal Graph Problem Zoo

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Fluschnik, T., Molter, H., Niedermeier, R., Renken, M., Zschoche, P. (2020). As Time Goes By: Reflections on Treewidth for Temporal Graphs. In: Fomin, F.V., Kratsch, S., van Leeuwen, E.J. (eds) Treewidth, Kernels, and Algorithms. Lecture Notes in Computer Science(), vol 12160. Springer, Cham. https://doi.org/10.1007/978-3-030-42071-0_6

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