×

Combinatorial growth in the modular group. (English) Zbl 1512.20154

Summary: We consider an exhaustion of the modular orbifold by compact subsurfaces and show that the growth rate, in terms of word length, of the reciprocal geodesics on such subsurfaces (so named low lying reciprocal geodesics) converges to the growth rate of the full set of reciprocal geodesics on the modular orbifold. We derive a similar result for the low lying geodesics and their growth rate convergence to the growth rate of the full set of closed geodesics.

MSC:

20F69 Asymptotic properties of groups
32G15 Moduli of Riemann surfaces, Teichmüller theory (complex-analytic aspects in several variables)
57K20 2-dimensional topology (including mapping class groups of surfaces, Teichmüller theory, curve complexes, etc.)
20H10 Fuchsian groups and their generalizations (group-theoretic aspects)
53C22 Geodesics in global differential geometry

References:

[1] F. P. Boca, V. Paşol, A. A. Popa, and A. Zaharescu, Pair correlation of angles between recip-rocal geodesics on the modular surface. Algebra Number Theory 8 (2014), no. 4, 999-1035 Zbl 1304.11073 MR 3248992 · Zbl 1304.11073
[2] J. Bourgain and A. Kontorovich, Beyond expansion II: low-lying fundamental geodesics. J. Eur. Math. Soc. (JEMS) 19 (2017), no. 5, 1331-1359 Zbl 1403.11054 MR 3635355 · Zbl 1403.11054
[3] J. Bourgain and A. Kontorovich, Beyond expansion, III: Reciprocal geodesics. Duke Math. J. 168 (2019), no. 18, 3413-3435 Zbl 1447.11079 MR 4034890 · Zbl 1447.11079
[4] P. Buser, Geometry and spectra of compact Riemann surfaces. Progr. Math. 106, Birkhäuser, Boston, MA, 1992 Zbl 0770.53001 MR 1183224 · Zbl 0770.53001
[5] D. Calegari and J. Louwsma, Immersed surfaces in the modular orbifold. Proc. Amer. Math. Soc. 139 (2011), no. 7, 2295-2308 Zbl 1276.20049 MR 2784794 · Zbl 1276.20049
[6] G. P. B. Dresden and Z. Du, A simplified Binet formula for k-generalized Fibonacci numbers. J. Integer Seq. 17 (2014), no. 4, Article 14.4.7 Zbl 1360.11031 MR 3181762 · Zbl 1360.11031
[7] V. Erlandsson, A remark on the word length in surface groups. Trans. Amer. Math. Soc. 372 (2019), no. 1, 441-455 Zbl 1429.30034 MR 3968775 · Zbl 1429.30034
[8] V. Erlandsson, H. Parlier, and J. Souto, Counting curves, and the stable length of currents. J. Eur. Math. Soc. (JEMS) 22 (2020), no. 6, 1675-1702 Zbl 1439.53040 MR 4092896 · Zbl 1439.53040
[9] V. Erlandsson and J. Souto, Counting curves in hyperbolic surfaces. Geom. Funct. Anal. 26 (2016), no. 3, 729-777 Zbl 1350.57017 MR 3540452 · Zbl 1350.57017
[10] J. Gilman, Informative words and discreteness. In Combinatorial group theory, discrete groups, and number theory, pp. 147-155, Contemp. Math. 421, American Mathematical Society, Providence, RI, 2006 Zbl 1116.30030 MR 2303833 · Zbl 1116.30030
[11] J. Gilman, Primitive curve lengths on pairs of pants. In Infinite group theory, pp. 141-155, World Scientific, Hackensack, NJ, 2018 MR 3586884 · Zbl 07909411
[12] J. Gilman and L. Keen, Word sequences and intersection numbers. In Complex manifolds and hyperbolic geometry (Guanajuato, 2001), pp. 231-249, Contemp. Math. 311, American Mathematical Society, Providence, RI, 2002 Zbl 1015.30021 MR 1940172 · Zbl 1015.30021
[13] J. Gilman and L. Keen, Cutting sequences and palindromes. In Geometry of Riemann sur-faces, pp. 194-216, London Math. Soc. Lecture Note Ser. 368, Cambridge University Press, Cambridge, 2010 Zbl 1194.20026 MR 2665010 · Zbl 1194.20026
[14] J. Gilman and L. Keen, Enumerating palindromes and primitives in rank two free groups. J. Algebra 332 (2011), 1-13 Zbl 1237.20023 MR 2774675 · Zbl 1237.20023
[15] J. Gilman and L. Keen, Lifting free subgroups of PSL.2;
[16] R/ to free groups. In Quasiconformal mappings, Riemann surfaces, and Teichmüller spaces, pp. 109-122, Contemp. Math. 575, American Mathematical Society, Providence, RI, 2012 Zbl 1256.30027 MR 2933896
[17] V. Guba and M. Sapir, On the conjugacy growth functions of groups. Illinois J. Math. 54 (2010), no. 1, 301-313 Zbl 1234.20041 MR 2776997 · Zbl 1234.20041
[18] A. Haas, Diophantine approximation on hyperbolic Riemann surfaces. Acta Math. 156 (1986), no. 1-2, 33-82 Zbl 0593.10028 MR 822330 · Zbl 0593.10028
[19] A. Kontorovich, Applications of thin orbits. In Dynamics and analytic number theory, pp. 289-317, London Math. Soc. Lecture Note Ser. 437, Cambridge University Press, Cambridge, 2016 Zbl 1406.11068 MR 3618792 · Zbl 1406.11068
[20] R. C. Lyndon and P. E. Schupp, Combinatorial group theory. Class. Math., Springer, Berlin, 2001 Zbl 0997.20037 MR 1812024 · Zbl 0997.20037
[21] W. Magnus, A. Karrass, and D. Solitar, Combinatorial group theory. 2nd edn., Dover Publica-tions, Inc., New York, 1976 Zbl 0362.20023 MR 0422434 · Zbl 0362.20023
[22] G. McShane and I. Rivin, Simple curves on hyperbolic tori. C. R. Acad. Sci. Paris Sér. I Math. 320 (1995), no. 12, 1523-1528 Zbl 0835.53050 MR 1340065 · Zbl 0835.53050
[23] B. T. Marmolejo, Growth of conjugacy classes of reciprocal words in triangle groups. Ph.D. thesis, City University of New York, 2020 MR 4187474
[24] M. Mirzakhani, Growth of the number of simple closed geodesics on hyperbolic surfaces. Ann. of Math. (2) 168 (2008), no. 1, 97-125 Zbl 1177.37036 MR 2415399 · Zbl 1177.37036
[25] M. Mureşan, A concrete approach to classical analysis. CMS Books in Mathematics/Ouvrages de Mathématiques de la SMC, Springer, New York, 2009 Zbl 1163.26001 MR 2456018 · Zbl 1163.26001
[26] P. S. Park, Conjugacy growth of commutators. J. Algebra 526 (2019), 423-458 Zbl 1447.20014 MR 3920909 · Zbl 1447.20014
[27] I. Rivin, Growth in free groups (and other stories)-twelve years later. Illinois J. Math. 54 (2010), no. 1, 327-370 Zbl 1225.05128 MR 2776999 · Zbl 1225.05128
[28] P. Sarnak, Reciprocal geodesics. In Analytic number theory, pp. 217-237, Clay Math. Proc. 7, American Mathematical Society, Providence, RI, 2007 Zbl 1198.11039 MR 2362203 · Zbl 1198.11039
[29] C. Series, The geometry of Markoff numbers. Math. Intelligencer 7 (1985), no. 3, 20-29 Zbl 0566.10024 MR 795536 · Zbl 0566.10024
[30] C. Traina, The conjugacy problem of the modular group and the class number of real quadratic number fields. J. Number Theory 21 (1985), no. 2, 176-184 Zbl 0567.10018 MR 808285 · Zbl 0567.10018
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.