English

A motivic Weil height machine for curves

Algebraic Geometry 2025-12-08 v1 Number Theory

Abstract

The rational points of a smooth curve XX over a number field kk map to the set of augmentations of the associated motivic algebra. An expectation, related to Kim's conjecture, is that for XX hyperbolic, the set of augmentations which come locally at each place of kk from a point is equal to the set of rational points. Our view is that this should provide a relative of the Grothendieck section conjecture which may be both more accessible, and more directly applicable, than the latter. As a first step in this direction, we extend aspects of the ``Weil height machine'' to the set of such augmentations, and use this to prove a Manin--Dem'janenko-style finiteness result for motivic augmentations for particular curves. Along the way, we determine the structure of the cohomological motive of a Gm\mathbb{G}_m-bundle over an algebraic variety as a highly structured algebra in the derived \infty-category of mixed motives with rational coefficients.

Keywords

Cite

@article{arxiv.2512.05284,
  title  = {A motivic Weil height machine for curves},
  author = {L. Alexander Betts and Ishai Dan-Cohen},
  journal= {arXiv preprint arXiv:2512.05284},
  year   = {2025}
}

Comments

92 pages, comments welcome

R2 v1 2026-07-01T08:10:26.245Z