Skip to main content

All Questions

Filter by
Sorted by
Tagged with
15 votes
1 answer
825 views

Weyl Groups as Galois groups

I am looking for explicit examples (for all positive integers $n \ge 5$) of degree $2n$ even polynomials $f(x)=h(x^2)$ over the field $\mathbb{Q}$ of rational numbers such that the Galois groups of $...
Yuri Zarhin's user avatar
  • 5,050
13 votes
2 answers
2k views

Galois group of a product of polynomials

How can I compute the Galois group of the polynomial $fg\in K[x]$ assuming that I know the Galois groups of $f\in K[x]$ and $g\in K[x]$? Let's suppose for simplicity that the field $K$ is perfect.
roger123's user avatar
  • 2,782
13 votes
0 answers
247 views

Galois groups of special polynomials

This question is motivated by long experiments with GAP. Call a monic polynomial with integer coefficients special in case it is irreducible and has only coefficients $-1$, $0$ or $1$. Let $n \geq 5$....
Mare's user avatar
  • 26.5k
7 votes
1 answer
282 views

Galois groups of truncated $\cosh(x)$ Taylor polynomials and related results?

(Part of this question was written with ChatGPT because english is not my native language). I am currently translating my diploma thesis from 2010 in english and thought to think about the topic again:...
mathoverflowUser's user avatar
4 votes
0 answers
180 views

Subgroups that conjugate-cover the ambient group

Let $G$ be a finite group, and suppose that a set of proper subgroups $H_1,\dotsc,H_n$ satisfy $G=\bigcup_{g\in G}\bigcup_{i=1}^nH_i^g$, where $H_i^g$ is the conjugate of $H_i$ by $g$. In this case, ...
Nicolas Banks's user avatar
1 vote
0 answers
85 views

inverse Galois problem on cyclic groups

It is known that the splitting field of $x^{p^n}-x$ over $\mathbb{F}_p$ is $\mathbf{Gal}(\mathbb{F}_{p^n}/\mathbb{F}_p)\cong\mathbb{Z}/n\mathbb{Z}$ and the splitting field of $\Phi_n(x)$ over $\mathbb{...
user537897's user avatar