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Turán Type Results for Distance Graphs

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Abstract

The classical Turán theorem determines the minimum number of edges in a graph on n vertices with independence number \(\alpha \). We consider unit-distance graphs on the Euclidean plane, i.e., graphs \( G = (V,E) \) with \( V \subset {\mathbb {R}}^2 \) and \( E = \{\{\mathbf{x}, \mathbf{y}\}: |\mathbf{x}-\mathbf{y}| = 1\} \), and show that the minimum number of edges in a unit-distance graph on n vertices with independence number \( \alpha \leqslant \lambda n \), \( \lambda \in [\frac{1}{4}, \frac{2}{7}] \), is bounded from below by the quantity \( \frac{19 - 50 \lambda }{3} n \), which is several times larger than the general Turán bound and is tight at least for \( \lambda = \frac{2}{7} \).

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References

  1. Brass, P., Moser, W., Pach, J.: Research Problems in Discrete Geometry. Springer, New York (2005)

    MATH  Google Scholar 

  2. Croft, H.T.: Incident incidents. Eureka 30, 22–26 (1967)

    Google Scholar 

  3. Erdős, P.: On sets of distances of \(n\) points. Am. Math. Mon. 53, 248–250 (1946)

    Article  MathSciNet  MATH  Google Scholar 

  4. Fajtlowicz, S.: Independence, clique size and maximum degree. Combinatorica 4(N1), 35–38 (1984)

    Article  MathSciNet  MATH  Google Scholar 

  5. Fraughnaugh, K.L., Locke, S.: \(11/30\) finding large independent sets in connected triangle-free 3-regular graphs. J. Comb. Theory 65(N1), 51–72 (1995)

    Article  MathSciNet  MATH  Google Scholar 

  6. Fraughnaugh, K.L., Locke, S.: Finding independent sets in triangle-free graphs. SIAM J. Discrete Math. 9(N4), 674–681 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  7. Fraughnaugh, K.L., Locke, S.: Lower bounds on size and independence in \(K_4\)-free graphs. J. Graph Theory 26(N2), 61–71 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  8. Kokotkin, A.A.: On large subgraphs of a distance graph which have small chromatic number. Math. Notes 96(N2), 298–300 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  9. Larman, D.G., Rogers, C.A.: The realization of distances within sets in Euclidean space. Mathematika 19, 1–24 (1972)

    Article  MathSciNet  MATH  Google Scholar 

  10. Locke, S., Lou, F.: Finding independent sets in \(K_{4}\)-free 4-regular connected graphs. J. Comb. Theory, Ser. B 71, N1 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  11. Raigorodskii, A.M.: Coloring distance graphs and graphs of diameters. In: Pach, J. (ed.) Thirty Essays on Geometric Graph Theory, pp. 429–460. Springer, New York (2013)

  12. Raigorodskii, A.M.: Cliques and cycles in distance graphs and graphs of diameters. Discrete Geom. Algebr. Comb. AMS Contemp. Math. 625, 93–109 (2014)

    MathSciNet  MATH  Google Scholar 

  13. Turán, P.: On an extremal problem in graph theory. Mat. Fiz. Lapok 48, 436–452 (1941) (in Hungarian)

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Acknowledgments

This work is done under the financial support of the following grants: the Grant 15-01-00350 of Russian Foundation for Basic Research, the Grant NSh-2964.2014.1 supporting leading scientific schools of Russia.

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Correspondence to Andrei M. Raigorodskii.

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Editor in Charge: János Pach

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Shabanov, L.E., Raigorodskii, A.M. Turán Type Results for Distance Graphs. Discrete Comput Geom 56, 814–832 (2016). https://doi.org/10.1007/s00454-016-9817-z

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