"editing and improving tag-infos should certainly be encouraged. However, it seems that not many users of this site find the time to do this". I don't think it's a matter of time. Indeed, the site's feature for this are very poor, at least to my understanding. Edits would typically require discussion, and a discussion is not really possible, except specifically posting on meta for this, which is not practical, and discouraging for minor issues. — YCor 1 hour ago
6
Let $n\ge 1$ be an integer and let us work over the field of complex numbers. Let $\mathcal{R}_n$ denote the set of rational conic bundles $\pi\colon X\to \mathbb{P}^n$ (morphisms such that the generic fibre is a geometry irreducible conic and $X$ is rational), up to square equivalence: two conic...
1
Consider the quadratic forms
$$
Q_1 = x^2 + y^2 - (t^2+1)z^2,\qquad Q_2 = x^2 + y^2 - z^2
$$
over the rational function field $\mathbb{F}_p(t)$, where $p > 2$ is a prime such that $t^2 + 1$ is irreducible over $\mathbb{F}_p$, i.e., $p \equiv 3 \ (\mathrm{mod} \ 4)$.
These forms are isomorphic ov...
1) In the following OEIS Sequence, what is the meaning of One alphabet labeled, the other $3$ unlabeled?
The number of Lyndon words (aperiodic necklaces) with $4n$ beads of $4$ colors, $n$ beads of each color. One color labeled, the other $3$ unlabeled.
$1, 52, 5133, 656880, 97772875, 1603...
There are 7 occurrences of lmis, whose tag info is "Linear Matrix Inequalities (LMIs)". I suggest to replace this tag with non-existing linear-matrix-inequalities since tags are usually not abbreviations.
