Mumford-Tate groups of 1-motives and Weil pairing

Cristiana Bertolin; Patrice Philippon

doi:10.1016/j.jpaa.2024.107702

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arXiv · 2210.16301

Mumford-Tate groups of 1-motives and Weil pairing

Cristiana Bertolin·Patrice Philippon

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Abstract

We show how the geometry of a 1-motive $M$ (that is existence of endomorphisms and relations between the points defining it) determines the dimension of its motivic Galois group ${\mathcal{G}}{\mathrm{al}}_{\mathrm{mot}}(M)$. Fixing periods matrices $\Pi_M$ and $\Pi_{M^*}$ associated respectively to a 1-motive $M$ and to its Cartier dual $M^*,$ we describe the action of the Mumford-Tate group of $M$ on these matrices. In the semi-elliptic case, according to the geometry of $M$ we classify polynomial relations between the periods of $M$ and we compute exhaustively the matrices representing the Mumford-Tate group of $M$. This representation brings new light on Grothendieck periods conjecture in the case of 1-motives.

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BibTeX RIS

Cristiana Bertolin, Patrice Philippon. 2022-10-28. Mumford-Tate groups of 1-motives and Weil pairing. https://doi.org/10.1016/j.jpaa.2024.107702

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