Talk:Superselection

1

Well, I think the run-up on the representations here is trying to talk about the decomposition into isotypic submodules, not into irreducibles. Charles Matthews 11:50, 12 Oct 2004 (UTC)

I agree, but that is the least of the problems with the article! Geometry guy 22:41, 19 September 2008 (UTC)

2

This is completely incomprehensible to someone well versed in basic quantum mechanics but not formal algebraic methods. It would be nice to explain things to people who don't already understand them! <end rant :P > —Preceding unsigned comment added by 98.216.104.210 (talk) 07:59, 22 October 2008 (UTC)

I agree, the article ought to be made accessible to those who have studied quantum mechanics but not representation theory, possibly by adding a section that restates the section "Relationship to symmetry" in language like "consider states psi in a Hilbert space H, and a set of operators A that act on psi . . . " If someone else can do it, great. If not I'll try to add something myself when I have a bit more time. -- Tim314 (talk) 00:21, 24 November 2008 (UTC)

This could help: . Boris Tsirelson (talk) 18:07, 8 February 2016 (UTC)

3

Is it not important to precise that we are in 3d, in the section "continuous symmetry" ? If not, the second homotopy group has no meaning ?

4

Perhaps I've misunderstood, but isn't the example trivial, because a particle constrained to a closed loop will have psi(x) = psi(x+L)? More examples would also be nice, but I don't currently know enough about this topic to do that myself. ~2026-32712-96 (talk) 05:13, 2 June 2026 (UTC)