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arXiv · 1909.08900

Lifting iterated Frobenius over $W_n(k)$

Yukihide Takayama
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Abstract

Let $X$ be a smooth scheme over a perfect field $k$ of positive characteristic. M.V.~Nori and V.~Srinivas studied infinitesimal liftings of Frobenius morphism $F:X\to X$. Namely, given a Frobenius lifting $F_Y: Y\to Y$ over $W_{n-1}(k)$ the obstruction of lifting $F_Y$ over $W_n(k)$ is a class in $H^1(X, T_X\tensor B_1\Omega^1_{X/k})$. We give a modified version of their theory and applications, in which we consider lifting $(n-1)$th iterated Frobenius $F^{n-1}:X\to X$ directly over $W_n(k)$.

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Yukihide Takayama. 2019-09-19. Lifting iterated Frobenius over $W_n(k)$. https://arxiv.org/abs/1909.08900

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