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3 votes
0 answers
182 views

Algebraic properties of Witt vectors $W(K^{\flat\circ})$, $K$ a characteristic 0 perfectoid field

Let $K$ be as in the title with tilt $K^\flat$. $W = W(K^{\circ\flat})$ satisfies a universal property: it is the unique $p$-adically complete $p$-torsion free $\mathbb{Z}_p$-algebra $A$ with $A / pA \...
Vik78's user avatar
  • 658
1 vote
0 answers
227 views

Deformations over $A_{\inf}$

Setup: Let $K$ be a perfectoid field of characteristic $0$ with tilt $K^{\flat}$. Let $A_{\inf}=W(\mathcal{O}_{K^{\flat}})$ be the infinitesimal period ring. Let $\mathcal{X}$ be a flat, projective $\...
Kostas Kartas's user avatar
8 votes
1 answer
2k views

Some questions from the paper by Scholze-Weinstein

The following is from the paper by Scholze-Weinstein on moduli of $p$ divisible groups. My question is from a part of Lemma 4.1.7: If $R$ is a semiperfect ring, then the canonical map $W(R^{\flat}) \...
Ashutosh RC's user avatar
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 ...
Asvin's user avatar
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