Open Access
2015 Computing quadratic function fields with high 3-rank via cubic field tabulation
P. Rozenhart, M.J. Jacobson, Jr, R. Scheidler
Rocky Mountain J. Math. 45(6): 1985-2022 (2015). DOI: 10.1216/RMJ-2015-45-6-1985
Abstract

In this paper, we present extensive numerical data on quadratic function fields with non-zero 3-rank. We use a function field adaptation of a method due to Belabas for finding quadratic number fields of high 3-rank. Our algorithm relies on previous work for tabulating cubic function fields of bounded discriminant \cite {Pieter3} but includes a significant novel improvement when the discriminants are imaginary. We provide numerical data for discriminant degree up to 11 over the finite fields $\mathbb{F}_5, \mathbb{F}_7, \mathbb{F}_11$ and $\mathbb{F}_13$ and $\mathbb{F}_13$. In addition to presenting new examples of fields of minimal discriminant degree with a given 3-rank, we compare our data with a variety of heuristics on the density of such fields with a given 3-rank, which in most cases supports their validity.

References

1.

Jeffrey D. Achter, The distribution of class groups of function fields, J. Pure Appl. Alg. 204 (2006), 316–333.  MR2184814 1134.11042 10.1016/j.jpaa.2005.04.003 Jeffrey D. Achter, The distribution of class groups of function fields, J. Pure Appl. Alg. 204 (2006), 316–333.  MR2184814 1134.11042 10.1016/j.jpaa.2005.04.003

2.

––––, Results of Cohen-Lenstra type for quadratic function fields, Contemp. Math. 463, American Mathermatical Society, Providence, RI, 2008.  MR2459984 1166.11018 10.1090/conm/463/09041 ––––, Results of Cohen-Lenstra type for quadratic function fields, Contemp. Math. 463, American Mathermatical Society, Providence, RI, 2008.  MR2459984 1166.11018 10.1090/conm/463/09041

3.

Emil Artin, Quadratische Körper im Gebiete der höheren Kongruenzen I, Math. Z. 19 (1924), 153–206.  MR1544651 10.1007/BF01181074 Emil Artin, Quadratische Körper im Gebiete der höheren Kongruenzen I, Math. Z. 19 (1924), 153–206.  MR1544651 10.1007/BF01181074

4.

Mark Bauer, Michael J. Jacobson, Jr., Yoonjin Lee and Renate Scheidler, Construction of hyperelliptic function fields of high three-rank, Math. Comp. 77 (2008), 503–530.  MR2353964 1131.11073 10.1090/S0025-5718-07-02001-7 Mark Bauer, Michael J. Jacobson, Jr., Yoonjin Lee and Renate Scheidler, Construction of hyperelliptic function fields of high three-rank, Math. Comp. 77 (2008), 503–530.  MR2353964 1131.11073 10.1090/S0025-5718-07-02001-7

5.

Karim Belabas, On quadratic fields with large $3$-rank, Math. Comp. 73 (2004), 2061–2074.  MR2059751 1051.11055 10.1090/S0025-5718-04-01632-1 Karim Belabas, On quadratic fields with large $3$-rank, Math. Comp. 73 (2004), 2061–2074.  MR2059751 1051.11055 10.1090/S0025-5718-04-01632-1

6.

Lisa Berger, Jing-Long Hoelscher, Yoonjin Lee, Jennifer Paulhus and Renate Scheidler, The $l$-rank structure of a global function field, Fields Inst. Comm. 60, American Mathematical Society, 2011.  MR2777803 1247.11143 Lisa Berger, Jing-Long Hoelscher, Yoonjin Lee, Jennifer Paulhus and Renate Scheidler, The $l$-rank structure of a global function field, Fields Inst. Comm. 60, American Mathematical Society, 2011.  MR2777803 1247.11143

7.

Bryden Cais, Jordan S. Ellenberg and David Zureick-Brown, Random Dieudonné modules, random $p$-divisible groups, and random curves over finite fields, J. Inst. Math. Jussieu 12 (2013), 651–676.  MR3062874 10.1017/S1474748012000862 Bryden Cais, Jordan S. Ellenberg and David Zureick-Brown, Random Dieudonné modules, random $p$-divisible groups, and random curves over finite fields, J. Inst. Math. Jussieu 12 (2013), 651–676.  MR3062874 10.1017/S1474748012000862

8.

Henri Cohen and Hendrik W. Lenstra, Jr., Heuristics on class groups, Lect. Notes Math. 1052, Springer, Berlin, 1984.  MR750661 Henri Cohen and Hendrik W. Lenstra, Jr., Heuristics on class groups, Lect. Notes Math. 1052, Springer, Berlin, 1984.  MR750661

9.

––––, Heuristics on class groups of number fields, Lect. Notes Math. 1068, Springer, Berlin, 1984.  MR756082 0558.12002 10.1007/BFb0099440 ––––, Heuristics on class groups of number fields, Lect. Notes Math. 1068, Springer, Berlin, 1984.  MR756082 0558.12002 10.1007/BFb0099440

10.

Francisco Diaz y Diaz, On some families of imaginary quadratic fields, Math. Comp. 32 (1978), 637–650.  MR485775 0383.12005 10.1090/S0025-5718-1978-0485775-4 Francisco Diaz y Diaz, On some families of imaginary quadratic fields, Math. Comp. 32 (1978), 637–650.  MR485775 0383.12005 10.1090/S0025-5718-1978-0485775-4

11.

Iwan Duursma, Class numbers for some hyperelliptic curves, de Gruyter, Berlin, 1996.  MR1394925 0901.11020 Iwan Duursma, Class numbers for some hyperelliptic curves, de Gruyter, Berlin, 1996.  MR1394925 0901.11020

12.

Jordan Ellenberg, Akshay Venkatesh and Craig Westerland, Homological stability for Hurwitz spaces and the Cohen-Lenstra conjecture over function fields, available at http://arxiv.org/abs/0912.0325, 2009.  MR3488737 10.4007/annals.2016.183.3.1 Jordan Ellenberg, Akshay Venkatesh and Craig Westerland, Homological stability for Hurwitz spaces and the Cohen-Lenstra conjecture over function fields, available at http://arxiv.org/abs/0912.0325, 2009.  MR3488737 10.4007/annals.2016.183.3.1

13.

Ke Qin Feng and Shu Ling Sun, On class number of quadratic function fields, World Scientific Publishers, Teaneck, NJ, 1990.  MR1098044 0924.11089 Ke Qin Feng and Shu Ling Sun, On class number of quadratic function fields, World Scientific Publishers, Teaneck, NJ, 1990.  MR1098044 0924.11089

14.

Eduardo Friedman and Lawrence C. Washington, On the distribution of divisor class groups of curves over a finite field, de Gruyter, Berlin, 1989.  MR1024565 0693.12013 Eduardo Friedman and Lawrence C. Washington, On the distribution of divisor class groups of curves over a finite field, de Gruyter, Berlin, 1989.  MR1024565 0693.12013

15.

Christian Friesen, Class group frequencies of real quadratic function fields: the degree $4$ case, Math. Comp. 69 (2000), 1213–1228.  MR1659859 1042.11071 10.1090/S0025-5718-99-01154-0 Christian Friesen, Class group frequencies of real quadratic function fields: the degree $4$ case, Math. Comp. 69 (2000), 1213–1228.  MR1659859 1042.11071 10.1090/S0025-5718-99-01154-0

16.

D. Garton, Random matrices, the Cohen-Lenstra heuristics, and roots of unity, Alg. Num. Theor. 9 (2015), 149–-171.  MR3317763 D. Garton, Random matrices, the Cohen-Lenstra heuristics, and roots of unity, Alg. Num. Theor. 9 (2015), 149–-171.  MR3317763

17.

Derek Garton, private communication, 2010. ––––, Random matrices and the Cohen-Lenstra statistics for global fields with roots of unity, 2012, available at http://gradworks.umi.com/35/21/3521978.html.  MR3078415 Derek Garton, private communication, 2010. ––––, Random matrices and the Cohen-Lenstra statistics for global fields with roots of unity, 2012, available at http://gradworks.umi.com/35/21/3521978.html.  MR3078415

18.

Helmut Hasse, Arithmetische Theorie der kubischen Zahlkörper auf klassenkörpertheoretischer Grundlage, Math. Z. 31 (1930), 565–582.  MR1545136 10.1007/BF01246435 Helmut Hasse, Arithmetische Theorie der kubischen Zahlkörper auf klassenkörpertheoretischer Grundlage, Math. Z. 31 (1930), 565–582.  MR1545136 10.1007/BF01246435

19.

M.J. Jacobson, Jr., Y. Lee, R. Scheidler and H.C. Williams, Construction of all cubic function fields of a given square-free discriminant, Inter. J. Num. Theor. 11 (2015), 1839–1885.  MR3390254 10.1142/S1793042115500803 M.J. Jacobson, Jr., Y. Lee, R. Scheidler and H.C. Williams, Construction of all cubic function fields of a given square-free discriminant, Inter. J. Num. Theor. 11 (2015), 1839–1885.  MR3390254 10.1142/S1793042115500803

20.

Michael J. Jacobson, Jr., Shantha Ramachandran and Hugh C. Williams, Numerical results on class groups of imaginary quadratic fields, Lect. Notes Comp. Sci. 4076, Springer, Berlin, 2006.  MR2282917 1143.11370 10.1007/11792086_7 Michael J. Jacobson, Jr., Shantha Ramachandran and Hugh C. Williams, Numerical results on class groups of imaginary quadratic fields, Lect. Notes Comp. Sci. 4076, Springer, Berlin, 2006.  MR2282917 1143.11370 10.1007/11792086_7

21.

Donald E. Knuth, The art of computer programming, Volume 2, third Addison-Wesley Publishing Co., Reading, Mass., 1998.  MR3077153 Donald E. Knuth, The art of computer programming, Volume 2, third Addison-Wesley Publishing Co., Reading, Mass., 1998.  MR3077153

22.

Yoonjin Lee, Cohen-Lenstra heuristics and the Spiegelungssatz; function fields, J. Num. Theor. 106 (2004), 187–199.  MR2059070 1049.11121 10.1016/j.jnt.2004.01.001 Yoonjin Lee, Cohen-Lenstra heuristics and the Spiegelungssatz; function fields, J. Num. Theor. 106 (2004), 187–199.  MR2059070 1049.11121 10.1016/j.jnt.2004.01.001

23.

––––, The Scholz theorem in function fields, J. Num. Theor. 122 (2007), 408–414.  MR2292262 1155.11052 10.1016/j.jnt.2006.05.014 ––––, The Scholz theorem in function fields, J. Num. Theor. 122 (2007), 408–414.  MR2292262 1155.11052 10.1016/j.jnt.2006.05.014

24.

Gunter Malle, Cohen-Lenstra heuristic and roots of unity, J. Num. Theor. 128 (2008), 2823–2835.  MR2441080 1225.11143 10.1016/j.jnt.2008.01.002 Gunter Malle, Cohen-Lenstra heuristic and roots of unity, J. Num. Theor. 128 (2008), 2823–2835.  MR2441080 1225.11143 10.1016/j.jnt.2008.01.002

25.

––––, On the distribution of class groups of number fields, Exper. Math. 19 (2010), 465–474.  MR2778658 1297.11139 10.1080/10586458.2010.10390636 euclid.em/1317758105 ––––, On the distribution of class groups of number fields, Exper. Math. 19 (2010), 465–474.  MR2778658 1297.11139 10.1080/10586458.2010.10390636 euclid.em/1317758105

26.

Michael E. Pohst, On computing non-Galois cubic global function fields of prescribed discriminant in characteristic $>3$, Publ. Math. Debr. 79 (2011), 611–621.  MR2907993 10.5486/PMD.2011.5136 Michael E. Pohst, On computing non-Galois cubic global function fields of prescribed discriminant in characteristic $>3$, Publ. Math. Debr. 79 (2011), 611–621.  MR2907993 10.5486/PMD.2011.5136

27.

Pieter Rozenhart, Fast tabulation of cubic function fields, Ph.D. thesis, University of Calgary, 2009. Pieter Rozenhart, Fast tabulation of cubic function fields, Ph.D. thesis, University of Calgary, 2009.

28.

Pieter Rozenhart, Michael J. Jacobson, Jr. and Renate Scheidler, Tabulation of cubic function fields via polynomial binary cubic forms, Math. Comp. 81 (2012), 2335–2359.  MR2945159 1290.11154 10.1090/S0025-5718-2012-02591-9 Pieter Rozenhart, Michael J. Jacobson, Jr. and Renate Scheidler, Tabulation of cubic function fields via polynomial binary cubic forms, Math. Comp. 81 (2012), 2335–2359.  MR2945159 1290.11154 10.1090/S0025-5718-2012-02591-9

29.

Pieter Rozenhart and Renate Scheidler, Tabulation of cubic function fields with imaginary and unusual Hessian, Lect. Notes Comp. Sci. 5011, Springer, 2008.  MR2467858 1232.11129 10.1007/978-3-540-79456-1_24 Pieter Rozenhart and Renate Scheidler, Tabulation of cubic function fields with imaginary and unusual Hessian, Lect. Notes Comp. Sci. 5011, Springer, 2008.  MR2467858 1232.11129 10.1007/978-3-540-79456-1_24

30.

Victor Shoup, Number theory library $($NTL$)$, version 5.5.2, 2010, http://www.shoup.net/ntl. Victor Shoup, Number theory library $($NTL$)$, version 5.5.2, 2010, http://www.shoup.net/ntl.

31.

Herman te Riele and Hugh Williams, New computations concerning the Cohen-Lenstra heuristics, Exper. Math. 12 (2003), 99–113.  MR2002677 1050.11096 10.1080/10586458.2003.10504715 euclid.em/1064858787 Herman te Riele and Hugh Williams, New computations concerning the Cohen-Lenstra heuristics, Exper. Math. 12 (2003), 99–113.  MR2002677 1050.11096 10.1080/10586458.2003.10504715 euclid.em/1064858787

32.

Akshay Venkatesh and Jordan S. Ellenberg, Statistics of number fields and function fields, Volume II, Hindustan Book Agency, New Delhi, 2010.  MR2827801 1259.11106 Akshay Venkatesh and Jordan S. Ellenberg, Statistics of number fields and function fields, Volume II, Hindustan Book Agency, New Delhi, 2010.  MR2827801 1259.11106

33.

Colin Weir, Renate Scheidler and Everett W. Howe, Constructing and tabulating dihedral function fields, Mathematical Science Publishers, Berkeley, CA, 2013.  MR3207431 Colin Weir, Renate Scheidler and Everett W. Howe, Constructing and tabulating dihedral function fields, Mathematical Science Publishers, Berkeley, CA, 2013.  MR3207431
Copyright © 2015 Rocky Mountain Mathematics Consortium
P. Rozenhart, M.J. Jacobson, Jr, and R. Scheidler "Computing quadratic function fields with high 3-rank via cubic field tabulation," Rocky Mountain Journal of Mathematics 45(6), 1985-2022, (2015). https://doi.org/10.1216/RMJ-2015-45-6-1985
Published: 2015
Vol.45 • No. 6 • 2015
Back to Top