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5 votes
0 answers
192 views

Image of $\gamma-1$ on etale $(\varphi,\Gamma)$-modules

Let $p\geq 3$ be a prime, $D$ be an etale $(\varphi,\Gamma)$-modules over the classical period ring $A_{\mathbb{Q}_p}=\mathbb{Z}_p[\![T]\!][1/T]^{\widehat{\phantom{xx}}}_p$ and $\gamma$ be a ...
6 votes
0 answers
630 views

On the Erratum to P. Scholze's "$p$-adic Hodge theory for rigid-analytic varieties"

I am trying to understand section (3) of the Erratum to P. Scholze's "$p$-adic Hodge theory for rigid-analytic varieties" in detail. In particular, there is the following sentence on page ...
3 votes
1 answer
369 views

Why is Fontaine's infinitesimal period ring $A_{\text{inf}}$ complete?

Fix a perfectoid field $K$ in mixed characteristic with ring of integers $\mathcal{O}$ and pseudo-uniformizer $\varpi$. Its tilt is the fraction field of $\mathcal{O}^{\flat}=\varprojlim_{x\mapsto x^{...
2 votes
1 answer
324 views

Rank of $\mathbb{Z}_{p}$-module $H_{et}^{i}(X,\mathbb{Z}_{p}(r))$

I want to ask the following question. Let $X$ be a smooth projective variety of dimension $d$ over $p$-adic field $k$ ( i.e. finite extension of $\mathbb{Q}_{p}$). Is it true that etale cohomology $H_{...
1 vote
1 answer
147 views

Triangularizability of induced $(\phi, \Gamma)$-modules

Let $K$ be a finite extension of $\mathbb{Q}_p$ and $L/K$ a finite unramified extension. Let $M$ be a $(\phi, \Gamma_L)$-module over the Robba ring of $L$ (with coefficients in some other $p$-adic ...
2 votes
0 answers
187 views

Does the map $\theta[1/p]: A_{\mathrm{inf}} \otimes \mathbb Q_p \to \mathbb C_p$ split?

This question might be very elementary to someone who knows p-adic hodge theory/perfectoid stuff etc. Recall that $\mathbb C_p = \hat{\overline{\mathbb Q_p}}$ and $\mathbb C_p^\flat$ is it's tilt. We ...
4 votes
1 answer
347 views

A Tate-Sen theorem mod $p$

Let $p$ be a prime number, $G=\textrm{Gal}(\overline{\mathbb{Q}}_p/\mathbb{Q}_p)$, and $\chi:G\rightarrow\mathbb{Z}_p^\times$ the cyclotomic character. Let $\mathbb{C}_p$ denote the completion of the ...
6 votes
0 answers
150 views

$SL_2(\mathbb{Z}_p)$ extension of a local field

Let $G$ be an arbitrary open group of $SL_2(\mathbb{Z}_p)$ and $K$ be a finite extension of $\mathbb{Q}_p$. Can we construct a Galois extension field $E$ of $K$ such that $\text{Gal}(E/K)\cong G$? ...
3 votes
0 answers
230 views

Independence of $p$ of Hodge-Tate weights

Let $X$ be a smooth and proper variety over $\mathbb{Q}$. Then for each prime $p$ we have the representation $R_p=H^i_{et}(X\times \overline{\mathbb{Q}_p}, \mathbb{Q}_p)$ of $\mathrm{Gal}(\overline{\...
4 votes
1 answer
278 views

Irreducible local Galois representation with arbitrary Hodge-Tate weights

Let $p$ be a prime and $M$ be a finite multiset of non-negative integers. Does there exist a continuous irreducible de Rham representation $\mathrm{Gal}(\overline{\mathbb{Q}_p}/\mathbb{Q}_p)\to GL_n(\...
8 votes
1 answer
1k views

Reference Request: Specialization map in Huber's Context

The specialization map $sp:\mathfrak{X}_\eta\to \mathfrak{X}_{red}$ has an important role in rigid analytic geometry. I tried looking in Huber's papers ("Continuous Valuations", "A generalization of ...
1 vote
1 answer
314 views

A question about Kato's explicit reciprocity law

In the paper Iwasawa Theory and F-analytic Lubin-tate $(\phi,\Gamma)$-modules Prop 3.4.2 says that for any $x\in{S}$, there exists (not uniuqely) $f(T)\in{B_{rig,F}^+}$ such that $f(u_n)=\log_{LT}(...
7 votes
1 answer
325 views

Injectivity of Frobenius on $A_{cris}$

I am reading Brinon, Conrad "Notes on $p$-adic Hodge theory" and I can't find any reference for the proof of Theorem 9.1.8, namely the injectivity of the Frobenius endomorphism of $A_{cris}$. Does ...
6 votes
0 answers
412 views

Two Definitions of Barsotti-Tate Representations

In different articles I have seen different definitions of Barsotti-Tate representations. I am wondering if and how these definitions are equivalent. In Section 1.1 of Conrad-Diamond-Taylor they say ...