Skip to main content
16 events
when toggle format what by license comment
Oct 4 at 23:03 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Jun 6 at 22:06 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Feb 7 at 21:07 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Oct 10, 2023 at 20:03 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Jun 12, 2023 at 17:03 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Feb 12, 2023 at 16:05 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Oct 15, 2022 at 15:07 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Sep 15, 2022 at 14:47 history edited LSpice CC BY-SA 4.0
Deleting spurious space in title, while this is on the front page
Sep 15, 2022 at 9:07 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Aug 16, 2022 at 8:38 answer added Александр Каренин timeline score: 0
Aug 9, 2022 at 19:24 history edited Александр Каренин CC BY-SA 4.0
edited title
Aug 9, 2022 at 18:39 comment added Александр Каренин If $K = \mathbb{Q}[\sqrt{-5}]$ and $\mathfrak{a}=(2,1+\sqrt{-5})$ then the $\mathfrak{a}$ as a module is isomorphic to $2\cdot\mathbb{Z} \oplus (1+\sqrt{-5})\cdot\mathbb{Z} \cong \mathbb{Z}^2$ and the elements in its integral basis are $2$ which is a vector $(2,0)^T$ and $1+\sqrt{-5}$ which is $(1,1)^T$. So basis of $\mathfrak{a}$ is $\begin{pmatrix} 2 & 1\\ 0 & 1 \end{pmatrix}$.
Aug 9, 2022 at 18:39 comment added Александр Каренин Yes! The $\mathbb{Z}$ is typo. I meant that $\mathfrak{a}$ is isomorphic to $\bigoplus_{i} a_i \cdot \mathbb{Z}$ because it is $\mathcal{O}_K$-module (for $\mathcal{O}_K$ - ring of integers of $K$) and therefore a $\mathbb{Z}$ module itself. I'll send an example in the next comment.
Aug 9, 2022 at 17:29 comment added LSpice $\mathbb{ZZ}$ in your title should be just $\mathbb Z$, right? Also, I am confused by your writing a fractional ideal as $\bigoplus_i a_i\cdot\mathbb Z$, where $a_i$ are integers … if you mean $a_i \in \mathbb Z$, then this can only give ideals of $\mathbb Z$; but, if you mean $a_i \in \mathcal O_K$, then it can only give ideals of $\mathcal O_K$, not fractional ideals, right?
S Aug 9, 2022 at 15:51 review First questions
Aug 9, 2022 at 16:46
S Aug 9, 2022 at 15:51 history asked Александр Каренин CC BY-SA 4.0