Questions tagged [p-adic]
The p-adic tag has no usage guidance.
92
questions
3
votes
0
answers
225
views
The points of $\operatorname{Spa}\mathbb{Z}_p$
$\DeclareMathOperator\Spa{Spa}$What are the points of $\Spa\mathbb{Z}_p$? I read in Scholze-Weinstein that this adic spectrum consists of 2 points, a special point, which corresponds to the pullback ...
- 675
2
votes
0
answers
57
views
Formulation of $p$-adic Haar measure decomposition
$\DeclareMathOperator\GL{GL}\DeclareMathOperator\vol{vol}\DeclareMathOperator\diag{diag}$Suppose:
$F$ is a non-archimedean local field,
$\mathcal{O} \subset F$ its ring of integers,
$\pi \in \mathcal{...
- 606
8
votes
0
answers
263
views
Interpretation of $p$-adic 'smoothness'
real case: In the very first course of Calculus, one learns that a real function $f \colon \mathbb{R} \to \mathbb{R}$ is called smooth, if it is differentiable as many times as one pleases. So the ...
- 606
2
votes
0
answers
124
views
Local Rankin-Selberg Zeta-function and Coates' p-adic L-Functions
$\DeclareMathOperator\Kern{Kern}\DeclareMathOperator\diag{diag}$
Let $F$ be a non-archimedean local field, $\mathcal{O}$ its ring of integers, $\mathfrak{p}$ its maximal ideal and $\pi$ a uniformizer.
...
- 606
5
votes
0
answers
221
views
A $p$-adic homotopy theory for non-simply connected spaces?
I'm looking to understand the state of the art for $p$-adic (unstable) homotopy theory of non-simply connected (non-nilpotent!) spaces. Ideally, I'd also like integral versions, e.g. things like ...
- 1,138
5
votes
0
answers
321
views
p-adic Hecke operators in the Iwahori-Hecke algebra $C_c(J\backslash G(F)/J)$
$\DeclareMathOperator\ch{ch}$Let $F$ be a non-archimedean local field, $\mathcal{O}$ its ring of integers, $\mathfrak{p}$ its maximal ideal and $\pi$ a uniformizer. I shall use $\kappa(F)$ to denote ...
- 606
1
vote
1
answer
88
views
Extension of morphisms in function fields
Let $k=\mathbb F_q\left(\left(\frac1T\right)\right)$, $\overline k$ be an algebraic closure of $k$ and $K$ be the completion of $\overline k$ for the $\frac1T$ valuation. Consider the morphism $\sigma:...
- 3,240
-1
votes
1
answer
355
views
$p$-adic number field $\mathbb{Q}_p $and algebraic numbers [closed]
As we all know, the complex number field $\mathbb{C}$ be a finite Galois extension field of the real number field that contains all algebraic numbers.
I want to know the proof of the following ...
- 11
2
votes
0
answers
174
views
$G_K$-fixed points of sections of affinoids on the Fargues-Fontaine curve
Let $K$ be a finite extension of $\mathbb{Q}_p$ and let $G_K=\mathrm{Gal}(\overline{K}/K)$ be its absolute Galois group. There are the Fargues-Fontaine analytic curves $Y_{FF}$ and $X_{FF}$ associated ...
- 643
19
votes
1
answer
813
views
Hensel's proof that $e$ is transcendental
When he introduced $p$-adic numbers, Kurt Hensel produced an incorrect local/global proof of the fact that $e$ is transcendental. Apparently, the intended proof goes along the following lines: ...
- 9,720
5
votes
0
answers
326
views
A local model of a Shimura variety and a local Shimura variety
I have a question about the book on p-adic geometry by Scholze and Weinstein.
There are two ‘local theories of Shimura varieties’ written in it.
The one is a local model of a Shimura variety. This is ...
- 111
3
votes
1
answer
380
views
Algebraic numbers in all $\mathbb Q_p$ [duplicate]
Do there exist non-rational algebraic numbers that belong to $\mathbb Q_p$ for all prime $p$? If yes, can one characterize them?
I spent several days for the first question, and I found nothing. The ...
- 3,240
5
votes
1
answer
354
views
Question about log and exp of a formal group law
Let $K$ be a finite extension of $\mathbb{Q}_p$. Let $F$ be a Lubin–Tate formal group law defined over $K$ with endomorphism $f(T)$ corresponding to $\pi$ (a uniformizer of $K$). Then one can define ...
1
vote
0
answers
89
views
What is the preimage of the maximal ideal under certain exponential functions?
I'm taking a shot in the dark with this question, so I apologize if it makes no sense.
Let $K$ be a finite extension of $\mathbb{Q}_p$, and let $K_n$ be the field obtained by adjoining the $n$-th ...
2
votes
0
answers
246
views
Existence of "nth root function" which is analytic
Let $K$ be a finite extension of $Q_p$. Let $q$ be the size of the residue field of $K$, and let $\pi$ be a uniformizer of $K$. Then $q/\pi$ is some power of $\pi$ up to a unit $u$ in $K$, say $q/\pi =...
6
votes
1
answer
689
views
Vector bundles on the various sites of a preperfectoid
Let $X$ be a preperfectoid space over $\mathrm{Spa}(\mathbb{Q}_p,\mathbb{Z}_p)$. It has several associated sites, with successively finer topologies: $$X_{an} \subset X_{et} \subset X_{proet} \subset ...
- 643
1
vote
1
answer
296
views
Looking for an electronic copy of Huber's Bewertungsspektrum und rigide Geometrie
Lately I've been trying (and have failed) to find an electronic copy of Huber's Bewertungsspektrum und rigide Geometrie, which (from what I understand) is the original reference developing the basics ...
- 9,387
1
vote
1
answer
266
views
Characters of p-adic units
Let $p$ be a prime and denote by $\mathbb{Z}_p^{\times}$ the group of $p$-adic units. Suppose that $\chi$ is a character $\chi: \mathbb{Z}_p^{\times} \rightarrow \mathbb{C}^{\times}$. Then it is well ...
- 59
5
votes
1
answer
516
views
Image of the ghost map of $p$-typical Witt vectors and $A$-ring structure of $W(A)$
For all ring with unit element $A$ let $W(A)$ be the ring of $p$-typical Witt vectors. Denote by $$\phi\;:\;W(A)\to A^{\mathbb{N}}$$
the ghost map, which is given by
$$\phi(a_0,a_1,a_2,\ldots)\;=\;(\...
- 165
1
vote
1
answer
147
views
Is the completion of the field generated by torsion points of a 1-dimensional formal group perfectoid?
Let $K$ be a finite extension of $\mathbb{Q}_p$ and let $G$ be a 1-dimensional formal group defined over $\mathcal{O}_K$. Consider the field $K_\infty$ obtained by adjoining to $K$ all the solutions ...
- 643
3
votes
0
answers
116
views
Homology of a fiber as a cotorsion product
Let $K$ be a field. For any differentially graded coalgebra $A$ over $K$, any differentially graded right $A$-comodule $M$ over $K$ and any differentially graded left $A$-comodule $N$ over $K$ let
$\...
- 1,191
6
votes
2
answers
1k
views
Vector bundles on adic spaces
Let $X = \mathrm{Spa}(A,A^+)$ be an analytic sheafy adic space. Let $\mathcal{E}$ be a locally finite free $\mathcal{O}_X$ sheaf. Does $\mathcal{E}$ correspond to a geometric vector bundle over $X$? ...
- 643
4
votes
3
answers
212
views
Is $K^\times/ F^\times$ compact for local fields?
Let $K/F$ be a finite extension of local fields (of characteristic 0). Is it true that the quotient group $K^\times/ F^\times$ is always compact?
I understand that if the extension is cyclic, it is ...
- 689
1
vote
0
answers
60
views
Continous morphisms of a local field with conditions in positive characteristic
Let $P$ be a an irreducible polynomial of $k:=\mathbb F_q(T)$, $\Omega_P$ be the completion of an algebraic closure $\overline{k_P}$ of $k_P$, the completion of $k$ for the topology induced by the $P$-...
- 3,240
1
vote
0
answers
331
views
On the paper "Patching and the p-adic local Langlands correspondence"
$\DeclareMathOperator\GL{GL}$The question is about the paper: Caraiani, Emerton, Gee, Geraghty, Paskunas, and Shin - Patching and the $p$-adic local Langlands correspondence. Let $F$ be a finite ...
- 423
3
votes
1
answer
120
views
Analytic p-adic functions that take an algebraic value
Suppose it exists $r\in\mathbb R$ such that the non constant p-adic function $f(z)=\sum_{n\ge0}a_nz^n$ ($a_n\in\mathbb C_p$) is defined on $\mathcal D=\{z\in\mathbb C_p\mid v_p(z)>r\}$. Does it ...
- 3,240
2
votes
0
answers
68
views
Zeroes of the Euler series
Consider a prime $p$. Let $f$ be the Euler series defined by $f(z)=\sum_{n\ge0}n!z^n\}$. It is defined and analytic over $\mathcal D=\{z\in\mathbb C_p\mid v_p(z)>-\frac1{p-1}\}$. I try to check if ...
- 3,240
6
votes
2
answers
698
views
Zero of the exponential p-adic
Consider the $p$-adic exponential defined over $\mathbb C_p$. One knows $\exp$ is analytic in the domain $\mathcal D=\{z\in\mathbb C_P\mid v_p(z)>\frac1{p-1}\}$. Does it exist an element $z_0\in\...
- 3,240
3
votes
0
answers
117
views
Composition in function fields
Let $k=\mathbb F_q\left(\!\left(\frac1T\right)\!\right)$. One has the map: $\circ:k\times\{v\in k\mid\deg(v)>0\}\to k$ defined by $f\circ g=\sum_{n\ge-m}a_ng^{-n}$ where $f=\sum_{n\ge-m}a_n\frac1{T^...
- 3,240
3
votes
2
answers
602
views
In a CM field, must all conjugates of an algebraic integer lying outside the unit circle lie outside the same?
This question is inspired from the post linked below:
Can an algebraic number on the unit circle have a conjugate with absolute value different from 1?
What I am curious about is the following: let $\...
- 709
2
votes
1
answer
327
views
Integrality certification for product of two matrices $A B^{-1}$
Let's consider two non-singular integer matrices $A,B \in\mathbb{Z}^{n\times n}$. I want a test to check if $A\times B^{-1}$ is integral (or no denominators). I am referring the unimodular ...
- 149
3
votes
0
answers
77
views
Freeness of completed homology over universal deformation ring
In Theorem 7.4 of the paper "patching and the $p$-adic Langlands program for $\mathrm{GL}2(\mathbf{Q}_p)$" (arXiv link), it is proved that in the minimally ramified case, the completed homology of ...
- 487
1
vote
0
answers
92
views
irrationality of Bessel function in $p$-adic
Let $J_0(z)=\sum_{n\ge 0}\frac{(-1)^n}{n!^2}\left(\frac z2\right)^{2n}$ be the Bessel function considered in $\mathbb C_p$. Let $\alpha\in\mathbb Q^*$ be in the convegence disk of $J_0$. Is $J_0(\...
- 3,240
0
votes
0
answers
126
views
continuous isomorphism of $p$-adic field
In Cassels-Frolich, one can read this theorem (page 57): Let $K$ be a finite finite separable extension of the valued field $(k,v)$. Let $\overline k$ be the completion of $k$ and $(K_j)_{1\le j\le r}$...
- 3,240
0
votes
0
answers
54
views
Comparison of growth of entire functions in a $p$-adic field
Let $p$ be a prime number, $\Omega_p$ be the spherically complete extension of $\mathbb C_p$. Consider two entire functions on $\Omega_p$: $f(z)=\sum_{n\ge 0}a_nz^n$ and $g(z)=\sum_{n\ge0}b_nz^n$. ...
- 3,240
3
votes
0
answers
232
views
A complete Tate Huber ring is Banachizable (maybe not)?
I have questions of technical nature.
A complete Tate Huber ring is a complete topological (commutative) ring $A$ admitting an open subring $A_0$ whose topology is the $\varpi A_0$-adic topology, for ...
- 5,392
2
votes
1
answer
151
views
Modulus of growth in $p$-adic spherically complete field of $\mathbb C_p$
Let $F$ be the spherically complete extension of $\mathbb C_p$ and $(a_n)_{n\in\mathbb N}$ be a sequence of $\mathbb C_p$ such that for all $r\in\mathbb R$, one has $$\lim_{n\to+\infty}|a_n|_pr^n=0.$$ ...
- 3,240
7
votes
1
answer
379
views
P-adic functions on annuli
It is known that a complex analytic function defined on an annulus, say, takes its maximum on the boundary. Does an analogue hold for $p$-adic analytic functions?
More precisely suppose we have a ...
- 145
1
vote
0
answers
178
views
Extension of $\mathbb C_p$?
Let $K/\mathbb Q$ be a finite algebraic extension. Consider a prime $p$ and $v$ be a valuation of $K$ above the valuation $v_p$ of $\mathbb Q_p$. Denote by $K_v$ a completion for the valuation $v$ of $...
- 3,240
2
votes
0
answers
70
views
Extension of valuations and completion
Let $L/K$ be a finite extension of fields where $K$ is a number field. Let $v$ be a valuation of $K$ and denotes by $K_v$ its completion for this valuation. One denotes $\tilde v$ be the valuation $...
- 3,240
3
votes
0
answers
139
views
Mixed characteristic in symplectic geometry
Are there any mixed-characteristic phenomena in symplectic geometry/mirror symmetry?
There are papers on symplectic geometry by Abouzaid (inspired by Kontsevich--Soibelman, I believe) in which there ...
user138661
1
vote
0
answers
155
views
Automorphisms of $\mathbb C_p$ with constraints
In Automorphisms of $\mathbb C_p$, K. Conrad showed that there exist uncountably many $\mathbb Q_p$-automorphisms of $\mathbb C_p$. I have a quite similar question.
Let $(a_n)_{n\in\mathbb N}$ and $(...
- 3,240
3
votes
1
answer
348
views
Analytic continuation of a $p$-adic function
Let $(a_n)_{n\in\mathbb N}$ and $(b_n)_{n\in\mathbb N}$ be sequences of $\mathbb Q_p$ such that the function $f:z\in\mathbb Q_p\to\sum_{n\ge0}a_nz^n+b_nz^{n+1}$converges in $\{|z|_p<1\}$. Assume ...
- 3,240
7
votes
1
answer
964
views
Convergence of a $p$-adic series
Let $K$ be a local field of characteristic $0$ with valuation $v$. I think
$$\lim_{\substack{q\in K\\q\to1}}\sum_{n\ge0}\prod_{j=1}^n\frac{q^j-1}{q-1}$$ converges to $\sum_{n\ge0}n!\in K$ but I did ...
- 3,240
2
votes
0
answers
67
views
Invariant compact in division ring
Let $K$ be a discrete valued (with discrete valuation $v$) complete local division ring with ring of valuation $V$. Let $F$ be a compact subset of $V$. Suppose that for all $x\in F$ and for all $y\in ...
- 3,240
12
votes
1
answer
915
views
Is the p-adic Lindemann-Weierstrass Conjecture still open?
The p-adic Lindemann-Weierstrass Conjecture: Let $\alpha_{1},\ldots,\alpha_{N}\in\overline{\mathbb{Q}_{p}}$
be distinct $p$-adic algebraic numbers satisfying $\left|\alpha_{n}\right|_{p}<p^{-\...
- 1,256
17
votes
1
answer
439
views
Centraliser of an absolute Galois group
Let $K$ be a finite extension of $\mathbb{Q}_p$.
Is the centraliser of $\operatorname{Gal}(\overline{K}/K)$ in $\operatorname{Gal}(\overline{\mathbb{Q}_p} / \mathbb{Q}_p)$ trivial ?
If yes, how can I ...
- 385
6
votes
1
answer
370
views
p-adic L-functions for (dual of) fine Selmer Groups
If $R(E/\Bbb Q_{\infty})$ is the fine Selmer group and $Y(E/\Bbb Q_{\infty})$ is its dual, then we know that $Y(E/\Bbb Q_{\infty})$ is a finitely generated $\Lambda$-module and by a theorem of Kato, ...
- 1,089
8
votes
1
answer
334
views
How to deduce Bernstein-Zelevinsky classification from the Langlands one
I am trying to understand the Langlands classification. To that end, I am trying to find how I could deduce the Bernstein-Zelevinsky classifcation from the second description of the Langlands ...
- 463
5
votes
0
answers
159
views
Arithmetic of Cuspidal Reps. Fundamental non split stratum and simple stratum
I started to read Colin Bushnell's notes on this title. The last theorem in the 3rd section claims that if $\pi$ is an irr. smooth rep. of $GL_N(F)$ containing a non-split fundamental stratum, then $\...
- 121