PreprintCC BY 4.0arXiv
Semisimplicity, purity and Mumford-Tate conjecture for hyper-Kähler varieties
Abstract
We prove the Mumford-Tate conjecture in every degree for hyper-Kähler varieties over fields finitely generated over ℚ. The proof establishes semisimplicity of ℓ-adic cohomology by eliminating the unipotent radical of the algebraic monodromy group of total cohomology. We also prove the weight-monodromy conjecture for hyper-Kähler varieties over p-adic fields. For hyper-Kähler varieties over number fields with b2≥ 4, we establish, after suitable finite extensions, strong compatibility of the associated Weil-Deligne representations valued in Mumford-Tate groups and its integral refinement away from finitely many primes.
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BibTeX
@misc{ito2026semisimplicity,
title = {{Semisimplicity, purity and Mumford-Tate conjecture for hyper-Kähler varieties}},
author = {Kazuhiro Ito and Haitao Zou},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07890},
eprint = {2610.07890},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07890},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Semisimplicity, purity and Mumford-Tate conjecture for hyper-Kähler varieties
AU - Kazuhiro Ito
AU - Haitao Zou
PY - 2026
DA - 2026/10/06
PB - arXiv
DO - 10.48550/arxiv.2610.07890
UR - https://arxiv.org/abs/2610.07890
AB - We prove the Mumford-Tate conjecture in every degree for hyper-Kähler varieties over fields finitely generated over ℚ. The proof establishes semisimplicity of ℓ-adic cohomology by eliminating the unipotent radical of the algebraic monodromy group of total cohomology. We also prove the weight-monodromy conjecture for hyper-Kähler varieties over p-adic fields. For hyper-Kähler varieties over number fields with b_2≥ 4, we establish, after suitable finite extensions, strong compatibility of the associated Weil-Deligne representations valued in Mumford-Tate groups and its integral refinement away from finitely many primes.
ER -