# Start a new discussion

## Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

## Discussion Tag Cloud

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeDec 18th 2014

Added to Klein geometry a section History with quotations for where exactly Klein actually speaks about $G/H$.

(This key passages is a bit hidden in Klein’s text, appearing at a somewhat unexpected point somewhere in the middle of a 35 page document.)

1. $Iso(d,1)$ contains parity-reversal and time-reversal. To obtain $\mathbb{R}^{d+1}$ from a quotient of $Iso(d,1)$, we must quotient these out. Therefore the stabilizer subgroup $H$ is $O(d,1)$ rather than $SO(d,1)$.

Anonymous

• CommentRowNumber3.
• CommentAuthorUrs
• CommentTimeMar 3rd 2019

thanks for catching. It was, luckily, correct in the table right below that erroneous line.

• CommentRowNumber4.
• CommentAuthorUrs
• CommentTimeApr 11th 2021

I have added the publication data and the DOI for the German original, and the projeceuclid-link for the English translation of:

will give this its own category:reference-page now

• CommentRowNumber5.
• CommentAuthorUrs
• CommentTimeJun 14th 2022

I have added a brief example (here) mentioning that the usual study of crystallography through crystallographic symmetry groups is much in the spirit of Klein geometry (even though I have not yet seen an author admitting this).

• Please log in or leave your comment as a "guest post". If commenting as a "guest", please include your name in the message as a courtesy. Note: only certain categories allow guest posts.
• To produce a hyperlink to an nLab entry, simply put double square brackets around its name, e.g. [[category]]. To use (La)TeX mathematics in your post, make sure Markdown+Itex is selected below and put your mathematics between dollar signs as usual. Only a subset of the usual TeX math commands are accepted: see here for a list.

• (Help)