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arXiv · 2303.00562

The diagonal of (3,3) fivefolds

Jan Lange·Bjørn Skauli
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Abstract

We show that a very general (3,3) complete intersection in $\mathbb{P}^7$ over an algebraically closed uncountable field of characteristic different from 2 admits no decomposition of the diagonal, in particular it is not retract rational. This strengthens Nicaise--Ottem's result, where stable irrationality in characteristic 0 was shown. The main tool is a Chow-theoretic obstruction which was found by Pavic--Schreieder, where quartic fivefolds are studied.

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Jan Lange, Bjørn Skauli. 2023-03-01. The diagonal of (3,3) fivefolds. https://arxiv.org/abs/2303.00562

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