Numerical spectrums control Cohomological spectrums
Abstract
Let be a smooth irreducible projective variety over a field of dimension Let be any field embedding. Let be a surjective endomorphism. We show that for every , the spectral radius of on the numerical group and on the -adic cohomology group are the same. As a consequence, if is -polarized for some , we show that the norm of every eigenvalue of on the -th cohomology group is for all This generalizes Deligne's theorem for Weil's Riemann Hypothesis to arbitary polarized endomorphisms and proves a conjecture of Tate. We also get some applications for the counting of fixed points and its ``moving target" variant. Indeed we studied the more general actions of certain cohomological coorespondences and we get the above results as consequences in the endomorphism setting.
Cite
@article{arxiv.2412.01216,
title = {Numerical spectrums control Cohomological spectrums},
author = {Junyi Xie},
journal= {arXiv preprint arXiv:2412.01216},
year = {2025}
}
Comments
18 pages