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arXiv · 1806.02777

Tensor and convolution direct image of $\ell$-adic sheaves

Antonio Rojas-León
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Abstract

Given a Galois \'etale map of varieties $\pi:Y\to X$ and an $\ell$-adic sheaf or derived category object $P\in D^b_c(Y,{\mathbb Q}_\ell)$, we study two cohomological operations: the tensor direct image and (in the case of perverse sheaves) the convolution direct image, which give objects of $D^b_c(X,{\mathbb Q}_\ell)$, and can be used to improve the estimates on some partial exponential sums and the number of rational points on certain varieties.

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Antonio Rojas-León. 2018-06-07. Tensor and convolution direct image of $\ell$-adic sheaves. https://arxiv.org/abs/1806.02777

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