English

Hodge structure on the fundamental group and its application to p-adic integration

Algebraic Geometry 2007-05-23 v1

Abstract

We study the unipotent completion ΠunDR(x0,x1,XK)\Pi^{DR}_{un}(x_0, x_1, X_K) of the de Rham fundamental groupoid [De] of a smooth algebraic variety over a local non-archimedean field K of characteristic 0. We show that the vector space ΠunDR(x0,x1,XK)\Pi^{DR}_{un}(x_0, x_1, X_K) possesses a distinguished element. In the other words, given a vector bundle E on XKX_K together with a unipotent integrable connection, we have {\sf a canonical} isomorphism Ex0Ex1E_{x_0}\simeq E_{x_1} between the fibers. The latter construction is a generalization of Colmez's p-adic integration (rk E=2) and Coleman's p-adic iterated integrals (XKX_K is a curve with good reduction). In the second part we prove that, if XK0X_{K_0} is a smooth variety over an unramified extension of Qp\mathbb{Q}_p with good reduction and rp12r \leq \frac{p-1}{2} then there is a canonical isomorphism ΠrDR(x0,x1,XK0)BDRΠret(x0,x1,XK0)BDR\Pi^{DR}_{r}(x_0, x_1, X_{K_0})\otimes B_{DR} \simeq \Pi^{et}_{r}(x_0, x_1, X_{\overline K_0}) \otimes B_{DR} compatible with the action of Galois group (Here ΠrDR(x0,x1,XK0)\Pi^{DR}_{r}(x_0, x_1, X_{K_0}) is the level r quotient of ΠunDR(x0,x1,XK)\Pi^{DR}_{un}(x_0, x_1, X_K)). In particularly, it implies the Crystalline Conjecture for the fundamental group [Shiho] (for rp12r \leq \frac{p-1}{2}) .

Keywords

Cite

@article{arxiv.math/0108109,
  title  = {Hodge structure on the fundamental group and its application to p-adic integration},
  author = {Vadim Vologodsky},
  journal= {arXiv preprint arXiv:math/0108109},
  year   = {2007}
}

Comments

44 pages

R2 v1 2026-07-22T16:40:00.439Z