Kalyan Banerjee ; Ankurjyoti Chutia ; Azizul Hoque - On the simultaneous 3-divisibility of class numbers of quadruples of real quadratic fields

hrj:17913 - Hardy-Ramanujan Journal, April 27, 2026, Volume 48 - 2025 - https://doi.org/10.46298/hrj.2026.17913
On the simultaneous 3-divisibility of class numbers of quadruples of real quadratic fieldsArticle

Authors: Kalyan Banerjee 1; Ankurjyoti Chutia ; Azizul Hoque 2

  • 1 SRM University AP
  • 2 Department of Mathematics, Gauhati University, Guwahati-781014, India.


In this paper, we construct infinitely many quadruples of real quadratic fields whose class numbers are all divisible by $3$. To the best of our knowledge, this is the first result towards the divisibility of the class numbers of certain tuples of real quadratic fields. At the end, we give an application of this result to produce some elliptic curves having a $3$-torsion subgroup.


Volume: Volume 48 - 2025
Published on: April 27, 2026
Accepted on: April 27, 2026
Submitted on: April 3, 2026
Keywords: 11R11; 11R29; 11G05, [MATH]Mathematics [math], [en] Hilbert class field, Iizuka's conjecture, Spiegelungssatz, Class number, Real quadratic field