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New York Journal of Mathematics
Volume 31 (2025), 568-588

  

Yasuhiro Ishitsuka, Tetsushi Ito, Tatsuya Ohshita, Takashi Taniguchi, and Yukihiro Uchida

Periods modulo p of integer sequences associated with division polynomials of genus 2 curves

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Published: March 25, 2025.
Keywords: Curves of genus 2, Jacobian, division polynomials.
Subject [2020]: Primary 11G30; Secondary 11B50, 14H25.

Abstract
We study an integer sequence associated with Cantor's division polynomials of a genus 2 curve having an integral point. We show that the reduction modulo p of such a sequence is periodic for all but finitely many primes p, and describe the relation between the period of the reduction modulo p of the sequence and the order of the integral point on the reduction modulo p in the Jacobian variety explicitly. This generalizes Ward's results on elliptic divisibility sequences associated with division polynomials of elliptic curves.

Acknowledgements

The authors would like to thank the referee for useful comments and suggestions. The work of Y. I. was supported by JSPS KAKENHI Grant Number 21K18577, 24K21512 and 21K13773. The work of T. I. was supported by JSPS KAKENHI Grant Number 21K18577, 24K21512 and 23K20786. The work of T. O. was supported by JSPS KAKENHI Grant Number 18H05233, 20K14295, 21K18577 and 24K21512. The work of T. T. was supported by JSPS KAKENHI Grant Number 21K18577, 24K21512 and 22H01115. The work of Y. U. was supported by JSPS KAKENHI Grant Number 21K18577, 24K21512 and 20K03517. A part of this work was done while the authors were supported by the Sumitomo Foundation FY2018 Grant for Basic Science Research Projects (Grant Number 180044). Most of calculations were done with the aid of the computer algebra systems Magma [2] and Sage [14].


Author information

Yasuhiro Ishitsuka
Institute of Mathematics for Industry
Kyushu University
Fukuoka, 819-0395, Japan

yishi1093@gmail.com

Tetsushi Ito
Department of Mathematics
Faculty of Science
Kyoto University
Kyoto 606-8502, Japan

tetsushi@math.kyoto-u.ac.jp

Tatsuya Ohshita
Department of Mathematics
Cooperative Faculty of Education
Gunma University
Maebashi, Gunma 371-8510, Japan

ohshita@gunma-u.ac.jp

Takashi Taniguchi
Department of Mathematics
Graduate School of Science
Kobe University
Kobe 657-8501, Japan

tani@math.kobe-u.ac.jp

Yukihiro Uchida
Department of Mathematical Sciences
Graduate School of Science
Tokyo Metropolitan University
1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan

yuchida@tmu.ac.jp