7 papers
An orthogonal perspective on Gauss composition
John Voight, Haochen Wu
We revisit Gauss composition over a general base scheme, with a focus on orthogonal groups. We show that the Clifford and norm functors provide an equivalence of stacks between bin…
The constructive inverse Galois problem via Hilbert modular forms: realizing the transitive group 17T7
Raymond van Bommel, Edgar Costa, Noam D. Elkies +3
We show how Hilbert modular forms can be used in the constructive inverse Galois problem over the rationals. In particular, we prove that the transitive permutation group 17T7, iso…
Hypergeometric Motives from Euler Integral Representations
Tyler L. Kelly, John Voight
We revisit certain one-parameter families of affine covers arising naturally from Euler's integral representation of hypergeometric functions. We introduce a partial compactificati…
Computing class groups and unit groups in Magma
Andreas-Stephan Elsenhans, John Voight
We describe the computation of class groups and unit groups of number fields as implemented in Magma (V2.29). After quickly reviewing the main algorithms based on factor bases, rel…
A framework for Tate modules of abelian varieties under isogeny
Sarah Frei, Katrina Honigs, John Voight
We explain the linear algebraic framework provided by Tate modules of isogenous abelian varieties in a category-theoretic way.
On abelian varieties whose torsion is not self-dual
Sarah Frei, Katrina Honigs, John Voight
We construct infinitely many abelian surfaces A defined over the rational numbers such that, for a prime ell <= 7, the ell-torsion subgroup of A is not isomorphic as a Galois modul…