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arXiv · 1811.05712

Rigid local systems with monodromy group the Conway group Co_2

Nicholas M. Katz·Antonio Rojas-León·Pham Huu Tiep
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Abstract

We first develop some basic facts about hypergeometric sheaves on the multiplicative group ${\mathbb G}_m$ in characteristic $p >0$. Certain of their Kummer pullbacks extend to irreducible local systems on the affine line in characteristic $p>0$. One of these, of rank $23$ in characteristic $p=3$, turns out to have the Conway group $\mathrm{Co}_2$, in its irreducible orthogonal representation of degree $23$, as its arithmetic and geometric monodromy groups.

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Nicholas M. Katz, Antonio Rojas-León, Pham Huu Tiep. 2018-11-14. Rigid local systems with monodromy group the Conway group Co_2. https://arxiv.org/abs/1811.05712

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