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arXiv · 2609.06625

Microlocalization and singular supports of constructible \'etale sheaves

Jiangnan Xiong·Enlin Yang
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Abstract

Let $X$ be a smooth scheme over a perfect field of characteristic $p>0$, and let $F$ be a constructible complex of finite Tor-dimension with finite coefficients of characteristic prime to $p$. We prove \[ {\rm SS}_\mu(F)= {\rm SS}(F), \] where ${\rm SS}_\mu(F)$ is Saito's microlocal singular support and ${\rm SS}(F)$ is Beilinson's singular support. This answers a question of Saito. As applications, we resolve another question of Saito regarding support estimates for microlocalization along a smooth closed subscheme, and we prove Saito's conjecture on characteristic classes (\emph{Invent. Math. 207: 597-695, 2017}), showing that the cohomological characteristic classes of Abbes and Saito are the cycle classes associated with the corresponding characteristic cycles.

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Jiangnan Xiong, Enlin Yang. 2026-09-06. Microlocalization and singular supports of constructible \'etale sheaves. https://arxiv.org/abs/2609.06625

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