3 papers
math.NT2025
The intrinsic subgroup of an elliptic curve and Mazur's torsion theorem
Takao Yamazaki, Yifan Yang, Hwajong Yoo +1
We define and study a biadditive symmetric (not necessarily perfect) pairing on the torsion part of the Picard group of a smooth projective curve…
math.NT2024
Motivic Gauss and Jacobi sums
Noriyuki Otsubo, Takao Yamazaki
We study the Gauss and Jacobi sums from a viewpoint of motives. We exhibit isomorphisms between Chow motives arising from the Artin-Schreier curve and the Fermat varieties over a f…
math.AG2023
Torsion birational motives of surfaces and unramified cohomology
Kanetomo Sato, Takao Yamazaki
Let and be smooth projective varieties over an algebraically closed field. Suppose that is a surface admitting a decomposition of the diagonal. We show that, away from…