J. Laga

collaborators

7 papers

math.AG2025

Polarizations, torsors and theta groups

Jef Laga

Let $I^» : A \to A^{\lor}$ be a polarization on an abelian variety over a field $k$ . If $k$ is not algebraically closed, there might not exist an ample line bundle on $A$ …

math.NT2025

Families of curves in Vinberg representations

Jef Laga, Beth Romano

Inspired by orbit parametrizations in arithmetic statistics, we explain how to construct families of curves associated to certain nilpotent elements in $Z / m Z$ -gra…

math.NT2025

Lower bounds on heights of odd degree points of hyperelliptic curves

Jef Laga, Jack A. Thorne

We develop a reduction theory for the representation of $SL_{n}$ on pairs of symmetric $n \times n$ matrices. We apply this theory to the pencils of quadrics arising from div…

math.NT2025

Kummers, spinors, and heights

Jef Laga, Jack A. Thorne

Let $f (x) = x^{2 g + 1} + c_{1} x^{2 g} + \dots + c_{2 g + 1} \in k [x]$ be a polynomial of nonzero discriminant, and let $J$ denote the Jacobian of the odd hyperelliptic curve $C : y^2 = f(…

math.AG2025

Vanishing criteria for Ceresa cycles

Jef Laga, Ari Shnidman

Let $C$ be a smooth projective curve, and let $J$ be its Jacobian. We prove vanishing criteria for the Ceresa cycle $I^º (C) \in CH_{1} (J) \otimes Q$ in the Chow group…

math.AG2024

Ceresa cycles of bielliptic Picard curves

Jef Laga, Ari Shnidman

We show that the Ceresa cycle $I^º (C_{t})$ of the genus $3$ curve $C_{t} : y^{3} = x^{4} + 2 t x^{2} + 1$ is torsion if and only if $Q_{t} = (3 t^{2} - 1, t)$ is a torsion point on the el…