Change of weights operations for triangulated $({\varphi},Γ)$-modules
Zichuan Wang
TL;DR
The work develops a general theory of change of weights for triangulated $(\varphi,\Gamma_K)$-modules in families, via pullback operations that adjust Sen weights and act compatibly with triangulations. It situates these weight shifts inside the analytic Emerton–Gee stack framework, defining weight-uniform trianguline substacks and showing their rigidity under the pullbacks $p_{i,\sigma}$ when regularity is preserved. For non-critical crystabelline cases with $K=\mathbb{Q}_p$, it proves a precise intertwining with translation functors on locally analytic $\mathrm{GL}_n(K)$-representations, establishing a 1-1 correspondence between weight shifts and automorphic translations using Ding’s construction. The arguments blend factorization of Sen polynomials, triangulation theory, Beilinson–Beilinson–Beilinson style universal extensions, and stack-theoretic pullbacks to connect $(\varphi,\Gamma_K)$-module operations with automorphic translation, yielding a robust, geometric framework for weight-shifting phenomena.
Abstract
Zhixiang Wu has shown the existence of "change of weights" operation on $(\varphi,Γ)$-modules in families (arxiv:2405.16637). We interpret it in the trianguline case as pullbacks with a discussion on related stacks. Finally, we prove that it intertwines well with translation functors via a 1-1 correspondence defined by Yiwen Ding (arXiv:2407.21237) in the non-critical crystabelline case.
