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No sublogarithmic-time approximation scheme for bipartite vertex cover

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Abstract

König’s theorem states that on bipartite graphs the size of a maximum matching equals the size of a minimum vertex cover. It is known from prior work that for every \(\epsilon > 0\) there exists a constant-time distributed algorithm that finds a \((1+\epsilon )\)-approximation of a maximum matching on bounded-degree graphs. In this work, we show—somewhat surprisingly—that no sublogarithmic-time approximation scheme exists for the dual problem: there is a constant \(\delta > 0\) so that no randomised distributed algorithm with running time \(o(\log n)\) can find a \((1+\delta )\)-approximation of a minimum vertex cover on 2-coloured graphs of maximum degree 3. In fact, a simple application of the Linial–Saks (Combinatorica 13:441–454, 1993) decomposition demonstrates that this run-time lower bound is tight. Our lower-bound construction is simple and, to some extent, independent of previous techniques. Along the way we prove that a certain cut minimisation problem, which might be of independent interest, is hard to approximate locally on expander graphs.

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References

  1. Åstrand, M., Polishchuk, V., Rybicki, J., Suomela, J., Uitto, J.: Local algorithms in (weakly) coloured graphs (2010). Manuscript, arXiv:1002.0125 [cs.DC]

  2. Czygrinow, A., Hańćkowiak, M., Wawrzyniak, W.: Fast distributed approximations in planar graphs. In: Proc. 22nd Symposium on Distributed Computing (DISC 2008), LNCS, vol. 5218, pp. 78–92. Springer, Berlin (2008). doi:10.1007/978-3-540-87779-0_6

  3. Diestel, R.: Graph Theory, 3rd edn. Springer, Berlin (2005). http://diestel-graph-theory.com/

  4. Göös, M., Hirvonen, J., Suomela, J.: Lower bounds for local approximation. In: Proc. 31st Symposium on Principles of Distributed Computing (PODC 2012), pp. 175–184. ACM Press, New York (2012). doi:10.1145/2332432.2332465

  5. Göös, M., Suomela, J.: No sublogarithmic-time approximation scheme for bipartite vertex cover. In: Proc. 26th Symposium on Distributed Computing (DISC 2012), LNCS, vol. 7611, pp. 181–194. Springer, Berlin (2012). doi:10.1007/978-3-642-33651-5_13

  6. Hassidim, A., Kelner, J.A., Nguyen, H.N., Onak, K.: Local graph partitions for approximation and testing. In: Proc. 50th Symposium on Foundations of Computer Science (FOCS 2009), pp. 22–31. IEEE Computer Society Press, Los Alamitos (2009). doi:10.1109/FOCS.2009.77

  7. Hoory, S., Linial, N., Wigderson, A.: Expander graphs and their applications. Bull. Am. Math. Soc. 43(4), 439–561 (2006). doi:10.1090/S0273-0979-06-01126-8

    Article  MATH  MathSciNet  Google Scholar 

  8. Janson, S.: Large deviations for sums of partly dependent random variables. Random Struct. Algor. 24(3), 234–248 (2004). doi:10.1002/rsa.v24:3

    Article  MATH  MathSciNet  Google Scholar 

  9. Kuhn, F., Moscibroda, T., Wattenhofer, R.: What cannot be computed locally! In: Proc. 23rd Symposium on Principles of Distributed Computing (PODC 2004), pp. 300–309. ACM Press, New York (2004). doi:10.1145/1011767.1011811

  10. Kuhn, F., Moscibroda, T., Wattenhofer, R.: The price of being near-sighted. In: Proc. 17th Symposium on Discrete Algorithms (SODA 2006), pp. 980–989. ACM Press, New York (2006). doi:10.1145/1109557.1109666

  11. Kuhn, F., Moscibroda, T., Wattenhofer, R.: Local computation: Lower and upper bounds (2010). Manuscript, arXiv:1011.5470 [cs.DC]

  12. Lenzen, C., Wattenhofer, R.: Leveraging Linial’s locality limit. In: Proc. 22nd Symposium on Distributed Computing (DISC 2008), LNCS, vol. 5218, pp. 394–407. Springer, Berlin (2008). doi:10.1007/978-3-540-87779-0_27

  13. Linial, N.: Locality in distributed graph algorithms. SIAM J. Comput. 21(1), 193–201 (1992). doi:10.1137/0221015

    Article  MATH  MathSciNet  Google Scholar 

  14. Linial, N., Saks, M.: Low diameter graph decompositions. Combinatorica 13, 441–454 (1993). doi:10.1007/BF01303516

    Article  MATH  MathSciNet  Google Scholar 

  15. Morgenstern, M.: Existence and explicit constructions of \(q + 1\) regular Ramanujan graphs for every prime power \(q\). J. Comb. Theory Ser. B 62(1), 44–62 (1994). doi: 10.1006/jctb.1994.1054

    Article  MATH  MathSciNet  Google Scholar 

  16. Naor, M., Stockmeyer, L.: What can be computed locally? SIAM J. Comput. 24(6), 1259–1277 (1995). doi:10.1137/S0097539793254571

    Article  MATH  MathSciNet  Google Scholar 

  17. Nguyen, H.N., Onak, K.: Constant-time approximation algorithms via local improvements. In: Proc. 49th Symposium on Foundations of Computer Science (FOCS 2008), pp. 327–336. IEEE Computer Society Press, Los Alamitos (2008). doi:10.1109/FOCS.2008.81

  18. Papadimitriou, C.H., Steiglitz, K.: Combinatorial Optimization: Algorithms and Complexity. Dover, Mineola (1998)

    MATH  Google Scholar 

  19. Parnas, M., Ron, D.: Approximating the minimum vertex cover in sublinear time and a connection to distributed algorithms. Theor. Comput. Sci. 381(1–3), 183–196 (2007). doi:10.1016/j.tcs.2007.04.040

    Article  MATH  MathSciNet  Google Scholar 

  20. Peleg, D.: Distributed Computing: A Locality-Sensitive Approach. SIAM Monographs on Discrete Mathematics and Applications. SIAM, Philadelphia (2000)

  21. Suomela, J.: Survey of local algorithms. ACM Comput. Surv. 45(2), 24:1–40 (2013). doi:10.1145/2431211.2431223. http://www.cs.helsinki.fi/local-survey/

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Acknowledgments

Many thanks to Valentin Polishchuk for discussions, and to anonymous reviewers for their helpful comments and suggestions. This work was supported in part by the Academy of Finland, Grants 132380 and 252018.

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Correspondence to Mika Göös.

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A preliminary version of this work [5] appeared in DISC 2012.

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Göös, M., Suomela, J. No sublogarithmic-time approximation scheme for bipartite vertex cover. Distrib. Comput. 27, 435–443 (2014). https://doi.org/10.1007/s00446-013-0194-z

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