Document Type

Conference Proceeding

Publication Date

2015

Publication Title

Advances in the Theory of Numbers: Proceedings of the Thirteenth Conference of the Canadian Number Theory Association

Abstract

We use a rigidity argument to prove the existence of two related degree twenty-eight covers of the projective plane with Galois group SU3(3).2 ∼= G2(2). Constructing corresponding two-parameter polynomials directly from the defining group-theoretic data seems beyond feasibility. Instead we provide two independent constructions of these polynomials, one from 3-division points on covers of the projective line studied by Deligne and Mostow, and one from 2-division points of genus three curves studied by Shioda. We explain how one of the covers also arises as a 2-division polynomial for a family of G2 motives in the classification of Dettweiler and Reiter. We conclude by specializing our two covers to get interesting three-point covers and number fields which would be hard to construct directly.

First Page

169

Last Page

206

DOI

10.1007/978-1-4939-3201-6_8

Comments

This is a pre-publication version of conference proceedings published in Advances in the Theory of Numbers: Proceedings of the Thirteenth Conference of the Canadian Number Theory Association. The final authenticated version is available online at: https://doi.org/10.1007/978-1-4939-3201-6_8

Rights

© Springer Science+Business Media New York 2015

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Mathematics Commons

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