« first day (1948 days earlier)      last day (1749 days later) » 

1:25 PM
Some discussion of Galois extensions in the main chatroom.
in Mathematics, 9 mins ago, by user193319
Are simple extensions always galois?
4
Q: Are there (finite) field extensions which aren't Galois?

XodarapLet $K=F(\alpha)$. It strikes me that there are two possibilities: $\alpha \in F$, in which case $K\cong F$ $\alpha\not\in F$, in which case $K$ is the splitting field of $(x-\alpha)$ (and hence Galois). (I actually think that even #1 might be described as a Galois extension - $|G(F/F)|=[F:F]...

4
Q: Are all Galois extensions simple?

John DoeI have been looking at Galois extensions and Galois groups and have been wondering if all Galois extensions are simple. I don't think this is true. For example with $\mathbb{Q}(\sqrt{2}, \sqrt{3}) = \mathbb{Q}(\sqrt{2} + \sqrt{3})$ would be a simple extension of $\mathbb{Q}$. With something li...

in Mathematics, 6 mins ago, by Alessandro Codenotti
@user193319 this is false in general. What's the standard example of a non Galois extension?
 

« first day (1948 days earlier)      last day (1749 days later) »