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数论 MSE 2 票 1 回答 35 浏览 未读

Reference request: Proof of the non-existence of three consecutive perfect powers

Math Admiral
I am looking for a reference—either a book or a specific paper—that contains the actual proof of the result that no three consecutive positive integers are perfect powers. While reading Wacław Sierpiński's 250 Problems in Elementary Number Theory, I came across a remark stating that A. Mąkowski...
数论 MSE -1 票 0 回答 20 浏览 未读

What's so special about the digit 6 here?

PapillonChiara
I ran a simulation where for each 2-digit combination with 30 symbols (so 0 to T), it checked, from base 2 to base 10,000, in how many bases that specific symbol combination resulted in a prime number. The top 10 were 65,6B,6H,6T,6N,61,6D,67,6J, and 6P. All starting with 6. Anyone have any idea...
代数几何 MSE 1 票 0 回答 48 浏览 未读

If $\mathrm{char} \, k \neq 2, 3$, then $R = k[x, y]/(y^2 - x^3 - 10)$ is a Dedekind domain

hdecristo
This problem is from the book Álgebra comutativa em quatro movimentos by Borges and Tengan. Let $k$ be a field of characteristic not equal to $2$ or $3$. Let $f(x, y) = y^2 - x^3 - 10$ and consider the ring $R = k[x, y]/(f(x, y))$. Show that $R$ is a Dedekind domain. Edit. We also have to assume...
解析数论 MSE 0 票 0 回答 17 浏览 未读

Understanding the definition of inert functions in Kiral–Petrow–Young

infiniteloopss
I am reading the paper Oscillatory Integrals with Uniformity in Parameters by Kiral, Petrow, and Young, and I am having trouble understanding the notion of an inert function introduced in Definition $2.1$. These are my confusions Since $X=X_T \in [1,\infty]$.Then if we consider a family of...
代数几何 MSE 2 票 0 回答 18 浏览 未读

How to compute Krull dimension concretely

hdecristo
I'm trying to solve the following problem from a commutative algebra book (Álgebra comutativa em quatro movimentos by Borges and Tengan). The question has 30 concrete examples of rings (mostly quotients), but I will restrict to two. Compute the Krull dimension of the following rings. $R =...
解析数论 MSE 0 票 0 回答 28 浏览 未读

Exercise 5 (Vinogradov-Korobov bound) in Tao's Math 254A Notes 5 (Bounding exponential sums and the zeta function)

Evaristesgun
$\newcommand{\e}[1]{\exp\left(#1\right)}$ $\newcommand{\le}{\leqslant}$ In Terry Tao's Math 254A Notes 5 (Bounding exponential sums and the zeta function), Exercise 5 outlines the derivation of the Vinogradov-Korobov bound for Dirichlet $L$-functions. Let $\chi$ be a non-principal character of...
数论 MSE 1 票 0 回答 51 浏览 未读

Rational number or transcendental number, but not algebraic irrational number

tteokbokki-Sulfate-NCetyl4
Let P(n) and Q(n) be two non-trivial polynomials in n with rational coefficients and z[P, Q] is the value of infinite sum of P(n)/Q(n) from n=1 to +∞ (only when it converges, in which the degree of Q should be larger than or equal to the degree of P plus 2). Claim: It is impossible for z[P,Q] to...
代数几何 MSE 0 票 0 回答 31 浏览 未读

Is it possible to have a singular plane curve such that the strict transform has a singularity "away" from original singualrity?

Adil Raza
Let $C$ be a plane curve and suppose, for simplicity, it has a singularity at the origin. Let $\tilde{C}$ be it's strict transform after blowing up $(0,0).$ Is it possible for $\tilde{C}$ to have a singular point not at the origin?
代数几何 MSE 0 票 0 回答 17 浏览 未读

Quasicoherent sheaves over stack quotient of affine $k$-scheme by affine group over $k$ are equivariant modules?

Jackozee Hakkiuz
These days I've been reading (Talpo and Vistoli)'s paper Infinite root stacks and quasi-coherent sheaves on infinite root stacks. At the moment I'm looking at their proposition 4.9....
L函数 MSE 3 票 1 回答 119 浏览 未读

Is Riemann zeta function essentially the only L-function with a pole?

bxhlywzzcr
I mean, if a function $F(s)$ is in Selberg class, and $F(s)$ has a pole of order m at $s=1$, is it true that there exists a function $G(s)$ in Selberg class such that $F(s)=\zeta^m(s)G(s)$, and $G$ is entire?
代数几何 MSE 3 票 1 回答 95 浏览 未读

Geometric interpretation of the annihilator of a zero divisor

Angeline Peng
Suppose $R$ is a reduced Noetherian ring. We know that $f \in R$ is a zero divisor if and only if $V(f)$ contains an irreducible component of $\mathrm{Spec} R$. I would like to know if one could use the irreducible components to say something about the annihilator of $f$ in $R$? (Perhaps it...
代数几何 MSE 1 票 0 回答 37 浏览 未读

A codimension of 0 with no irreducible components

Aubleu
I found this problem where I think there is a mistake but am not 100% sure: Let $Z$ be a closed subset of a topological space $X$. If $Z$ is irreducible we call codim($Z,X$) as the supremum of lengths of the chains of irreducible closed subsets of $X$ which contains $Z$: $$Z\subset Z_0\subsetneq...
L函数 MSE 0 票 0 回答 2 浏览 未读

Why must functions in Selberg class be of finite order?

bxhlywzzcr
One of the axioms for Selberg class is that for some natural number $m$, $(s-1)^mF(s)$ extends to an entire function of finite order. What is the use of "finite order"? If we allow it to be of infinite order, what will happen?
模形式 MSE 0 票 1 回答 9 浏览 未读

Do quadratic curves have L-functions?

bxhlywzzcr
Elliptic curves have L-functions that correspond to modular forms. Elliptic curves are degree 3 algebraic curves. I want to know if quadratic curves have L-functions. If they do, are these L-functions related to modular forms?
代数几何 MSE 0 票 0 回答 88 浏览 未读

How to prove that $\mathbb{P}^n_{\mathbb{Z}} \setminus D_+(x_i) \cong \mathbb{P}^{n-1}_{\mathbb{Z}}$?

Topo
I am currently studying algebraic geometry and trying to understand projective spaces. let $S = \mathbb{Z}[x_0, \dots, x_n]$ so that $\mathbb{P}^n_{\mathbb{Z}} = \operatorname{Proj}(S)$. I read that if we remove the standard open affine subset $D_+(x_i) = \{ \mathfrak{p} \in...
代数几何 MSE 1 票 1 回答 59 浏览 未读

Intuition behind the first exact sequence for Kahler differentials

Gold
I'm studying algebraic geometry and have a question on Kahler differentials. Let $k$ be a commutative ring with unit and $A$ a $k$-algebra. I already have the intuition if we picture $A$ as some ring of functions on $\operatorname{Spec}{A}$, the the module of relative Kahler differentials...
代数几何 MSE 1 票 1 回答 149 浏览 未读

What is the dimension of the affine variety $\mathbb{F}_p^1$?

Zoudelong
I'm self studying commutative algebra. Here is the question: Edit(Background and Definition): Let $k$ be a field, we define an affine variety $V\subseteq k^n$ as the set of common zeroes of some polynomials $f_1,\dots, f_m\in k[x_1,\dots, x_n]$, define its coordinate ring as $k[x_1,\dots,...
解析数论 MSE 0 票 0 回答 52 浏览 未读

An estimate for exponential sums

ouyang xuan
Given a real polynomial $f(x)=a_0x^d+\cdots+a_1 x$, I want to give a sharp estimate for $\sum_{n\le X} e(f(n))$. If $f(x)=ax$ is a linear function, we have $$\sum_{n\le X} e(\alpha n)\ll \min (X,\|\alpha\|^{-1});$$ If $f(x)\in\mathbb{Z}[x]$ where $p$ is a prime, using Weil's bound for...
代数几何 MSE 5 票 1 回答 138 浏览 未读

Why does the isomorphism of varieties “lines intersect / don’t intersect” argument work?

424
https://en.wikipedia.org/wiki/Rational_mapping The usual example is that $ \mathbb {P} _{k}^{2} $ is birational to the variety $ X $ contained in $ \mathbb {P} _{k}^{3} $ consisting of the set of projective points $ [w:x:y:z] $ such that $ xy-wz=0 $, but not isomorphic. Indeed, any two lines in...
代数数论 MSE 0 票 1 回答 38 浏览 未读

Regarding a claim about conjugacy of prime ideals in decomposition fields

Daniel Aricatt
This question follows from Lemma 6.1.1 from CH 6.1 of Field Arithmetic by Fried and Jarden. It is the subsection on Decomposition groups.' The following paragraph sets up the notation used. In the construction of Decomposition groups the chapter starts by defining $R$ to be an integrally closed...