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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeMay 11th 2022
   • PermaLink
   Author: Urs
   Format: MarkdownItexa stub, in order to make links work (this needed now at *[[symmetry protected topological phase]]* etc., but it has also long been requested at *[[Coleman-Mandula theorem]]*) <a href="https://ncatlab.org/nlab/revision/internal+symmetry/1">v1</a>, <a href="https://ncatlab.org/nlab/show/internal+symmetry">current</a>

   a stub, in order to make links work (this needed now at symmetry protected topological phase etc., but it has also long been requested at Coleman-Mandula theorem)

   v1, current

2. • CommentRowNumber2.
   • CommentAuthorUrs
   • CommentTimeMay 15th 2022
   • PermaLink
   Author: Urs
   Format: MarkdownItexadded one reference that makes the definition of internal symmetry in CMT fully explicit * [[Charles Zhaoxi Xiong]], p. 13 of: *Classification and Construction of Topological Phases of Quantum Matter* $[$[arXiv:1906.02892](https://arxiv.org/abs/1906.02892)$]$ (will try to find a more canonical reference for this). Also added a warning that the historical terminology at some point was the opposite to what it is today: > Beware that old historical articles (eg. [Barlow 1883](crystal#Barlow1883)) used "internal symmetry" to refer to [[crystallographic group|crystallographic symmetry]] which now is referred to as "spatial symmetry" and regarded as non-internal. <a href="https://ncatlab.org/nlab/revision/diff/internal+symmetry/3">diff</a>, <a href="https://ncatlab.org/nlab/revision/internal+symmetry/3">v3</a>, <a href="https://ncatlab.org/nlab/show/internal+symmetry">current</a>

   added one reference that makes the definition of internal symmetry in CMT fully explicit

   • Charles Zhaoxi Xiong, p. 13 of: Classification and Construction of Topological Phases of Quantum Matter $[$arXiv:1906.02892$]$

   (will try to find a more canonical reference for this).

   Also added a warning that the historical terminology at some point was the opposite to what it is today:

   Beware that old historical articles (eg. Barlow 1883) used “internal symmetry” to refer to crystallographic symmetry which now is referred to as “spatial symmetry” and regarded as non-internal.

   diff, v3, current