Skip to main content
Log in

Spectrum and combinatorics of two-dimensional Ramanujan complexes

  • Published:
Israel Journal of Mathematics Aims and scope Submit manuscript

Abstract

Ramanujan graphs have extremal spectral properties, which imply a remarkable combinatorial behavior. In this paper we compute the high dimensional Hodge–Laplace spectrum of Ramanujan triangle complexes, and show that it implies a combinatorial expansion property, and a pseudorandomness result. For this purpose we prove a Cheeger-type inequality and a mixing lemma of independent interest.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. N. Alon and F. R. K. Chung, Explicit construction of linear sized tolerant networks, Discrete Mathematics 72 (1988), 15–19.

    Article  MathSciNet  MATH  Google Scholar 

  2. N. Alon and V. D. Milman, λ1, isoperimetric inequalities for graphs, and superconcentrators, Journal of Combinatorial Theory. Series B 38 (1985), 73–88.

    Article  Google Scholar 

  3. A. Borel, Admissible representations of a semi-simple group over a local field with vectors fixed under an Iwahori subgroup, Inventiones Mathematicae 35 (1976), 233–259.

    Article  MathSciNet  MATH  Google Scholar 

  4. W. Casselman, On a p-adic vanishing theorem of Garland, Bulletin of the American Mathematical Society 80 (1974), 1001–1004.

    Article  MathSciNet  MATH  Google Scholar 

  5. W. Casselman, The unramified principal series of p-adic groups. I. The spherical function, Compositio Mathematica 40 (1980), 387–406.

    MathSciNet  MATH  Google Scholar 

  6. M. Cowling, U. Haagerup and R. Howe, Almost L 2 matrix coefficients, Journal für die Reine und Angewandte Mathematik 387 (1988), 97–110.

    MathSciNet  MATH  Google Scholar 

  7. D. I. Cartwright and T. Steger, Elementary symmetric polynomials in numbers of modulus 1, Canadian Journal of Mathematics 54 (2002), 239–262.

    Article  MathSciNet  MATH  Google Scholar 

  8. D. I. Cartwright, P. Solé and A. Żuk, Ramanujan geometries of type A˜n, Discrete Mathematics 269 (2003), 35–43.

    Article  MathSciNet  MATH  Google Scholar 

  9. B. Eckmann, Harmonische funktionen und randwertaufgaben in einem komplex, Commentarii Mathematici Helvetici 17 (1944), 240–255.

    Article  MathSciNet  MATH  Google Scholar 

  10. S. Evra, K. Golubev and A. Lubotzky, Mixing properties and the chromatic number of Ramanujan complexes, International Mathematics Research Notices 22 (2015), 11520–11548.

    MathSciNet  MATH  Google Scholar 

  11. J. Fox, M. Gromov, V. Lafforgue, A. Naor and J. Pach, Overlap properties of geometric expanders, Journal für die Reine und Angewandte Mathematik 671 (2012), 49–83.

    MathSciNet  MATH  Google Scholar 

  12. U. A. First, The Ramanujan property for simplicial complexes, preprint, arXiv:1605.02664.

  13. J. Friedman and N. Pippenger, Expanding graphs contain all small trees, Combinatorica 7 (1987), 71–76.

    Article  MathSciNet  MATH  Google Scholar 

  14. H. Garland, p-adic curvature and the cohomology of discrete subgroups of p-adic groups, Annals of Mathematics 97 (1973), 375–423.

    Google Scholar 

  15. A. Gundert and M. Szedlák, Higher dimensional Cheeger inequalities, in Computational Geometry SoCG’14, ACM, New York, 2014, pp. 181–188.

    Google Scholar 

  16. A. Gundert and U. Wagner, On expansion and spectral properties of simplicial complexes, Ph.D. thesis, ETH Zürich, Switzerland, 2013, Diss. ETH No. 21600 of Anna Gundert.

    MATH  Google Scholar 

  17. S. Hoory, N. Linial and A. Wigderson, Expander graphs and their applications, Bulletin of the American Mathematical Society 43 (2006), 439–562.

    Article  MathSciNet  MATH  Google Scholar 

  18. A. J. Hoffman, On eigenvalues and colorings of graphs, in Graph Theory and its Applications (Proc. Advanced Sem., Math. Research Center, Univ. of Wisconsin, Madison, Wis., 1969), Academic Press, New York, 1970, pp. 79–91.

    Google Scholar 

  19. M. H. Kang, W. C.W. Li and C. J. Wang, The zeta functions of complexes from PGL(3): a representation-theoretic approach, Israel Journal of Mathematics 177 (2010), 335–348.

    Article  MathSciNet  MATH  Google Scholar 

  20. W. C. W. Li, Ramanujan hypergraphs, Geometric and Functional Analysis 14 (2004), 380–399.

    Article  MathSciNet  MATH  Google Scholar 

  21. A. Lubotzky and R. Meshulam, A Moore bound for simplicial complexes, Bulletin of the London Mathematical Society 39 (2007), 353–358.

    Article  MathSciNet  MATH  Google Scholar 

  22. A. Lubotzky, R. Phillips and P. Sarnak, Ramanujan graphs, Combinatorica 8 (1988), 261–277.

    Article  MathSciNet  MATH  Google Scholar 

  23. A. Lubotzky, B. Samuels and U. Vishne, Ramanujan complexes of type A˜d, Israel Journal of Mathematics 149 (2005), 267–299.

    Article  MathSciNet  MATH  Google Scholar 

  24. A. Lubotzky, B. Samuels and U. Vishne, Explicit constructions of Ramanujan complexes of type A˜d, European Journal of Combinatorics 26 (2005), 965–993.

    Article  MathSciNet  MATH  Google Scholar 

  25. A. Lubotzky, Discrete Groups, Expanding Graphs and Invariant Measures, Progress in Mathematics, Vol. 125, Birkhäuser Verlag, Basel, 1994.

    MATH  Google Scholar 

  26. A. Lubotzky, Expander graphs in pure and applied mathematics, Bulletin of the American Mathematical Society 49 (2012), 113–162.

    Article  MathSciNet  MATH  Google Scholar 

  27. A. Lubotzky, Ramanujan complexes and high dimensional expanders, Japanese Journal of Mathematics 9 (2014), 137–169.

    Article  MathSciNet  MATH  Google Scholar 

  28. I. G. Macdonald, Symmetric Functions and Hall Polynomials, Oxford Mathematical Monographs, Clarendon Press, Oxford University Press, New York, 1979.

    MATH  Google Scholar 

  29. G. A. Margulis, Explicit group-theoretical constructions of combinatorial schemes and their application to the design of expanders and concentrators, Problemy Peredachi Informatsii 24 (1988), 51–60.

    MATH  Google Scholar 

  30. M. Papikian, On eigenvalues of p-adic curvature, Manuscripta Mathematica 127 (2008), 397–410.

    Article  MathSciNet  MATH  Google Scholar 

  31. O. Parzanchevski, Mixing in high-dimensional expanders, Combinatorics, Probability and Computing 26 (2017), 746–761.

    Article  MathSciNet  MATH  Google Scholar 

  32. O. Parzanchevski and R. Rosenthal, Simplicial complexes: Spectrum, homology and random walks, Random Structures & Algorithms 50 (2017), 225–261.

    Article  MathSciNet  MATH  Google Scholar 

  33. O. Parzanchevski, R. Rosenthal and R. J. Tessler, Isoperimetric inequalities in simplicial complexes, Combinatorica 36 (2016), 195–227.

    Article  MathSciNet  MATH  Google Scholar 

  34. P. Sarnak, Some Applications of Modular Forms, Cambridge Tracts in Mathematics, Vol. 99, Cambridge University Press, Cambridge, 1990.

  35. A. Sarveniazi, Explicit construction of a Ramanujan (n1, n2,...,nd−1)-regular hypergraph, Duke Mathematical Journal 139 (2007), 141–171.

    Article  MathSciNet  MATH  Google Scholar 

  36. M. Tadic, Classification of unitary representations in irreducible representations of general linear group (non-archimedean case), Annales Scientifiques de l’École Normale Supérieure 19 (1986), 335–382.

    Article  MathSciNet  MATH  Google Scholar 

  37. A. V. Zelevinsky, Induced representations of reductive p-adic groups. II. On irreducible representations of GL(n), Annales Scientifiques de l’École Normale Supérieure 13 (1980), 165–210.

    Article  MathSciNet  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Konstantin Golubev.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Golubev, K., Parzanchevski, O. Spectrum and combinatorics of two-dimensional Ramanujan complexes. Isr. J. Math. 230, 583–612 (2019). https://doi.org/10.1007/s11856-019-1828-z

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11856-019-1828-z

Navigation