User talk:JackSchmidt/Archives/2008/11

applications of vector spaces
Hi Jack,

I'm currently working on vector space. The article is in a decent intermediate state. One thing I'm thinking about, without much result so far, are applications of vector spaces. Do you have any ideas? Somehow, pretty much anything (involving some functions, say) is a vector space, so finding applications is either trivial, but giving specific items, which somehow illuminate the nature of v.spaces, is less easy. If you have a free moment, I'd appreciate if you could give some tips of what you deem essential in this respect (either at the article, the talk page, or whereever). Thank you, Jakob.scholbach (talk) 21:09, 14 October 2008 (UTC)


 * It's me again. Sorry to bug you all the time: the vector space article says (I did not write/know this) "The ultrafilter lemma, which is weaker than the axiom of choice, implies that all bases of a given vector space have the same "size", i.e. cardinality.". I have looked up a couple of books, but didn't find that statement. Do you know a reference for that? Thank you, Jakob.scholbach (talk) 20:48, 7 November 2008 (UTC)

Wikipedia's Expert Peer Review process (or lack of such) for Science related articles
Hi - I posted the section with the same name on my talk page. Could you take part in discussion ? Thanks ARP Apovolot (talk) 20:18, 25 October 2008 (UTC)

User: Shotwell suggested (on my talk page) "I would endorse a WP:EXPERTADVICE page that outlined the wikipedia policies and goals for researchers in a way that enticed them to edit here in an appropriate fashion. Perhaps a well-maintained list of expert editors with institutional affiliation would facilitate this sort of highly informal review process. I don't think anyone would object to a well-maintained list of highly-qualified researchers with institutional affiliation (but then again, everyone seems to object to something)."

We could start with that if you would agree ... - could you help to push his idea through Wikipedia bureaucracy ? Apovolot (talk) 16:27, 1 November 2008 (UTC)

a qustion
what do u meen by "wr" in the sentense

"Roughly speaking, K must be contained a subgroup of small index in one of the following groups unless n is smaller than 18: Sym(n−k) × Sym(k), Sym(n/2) wr Sym(2), Sym(2) wr Sym(n/2) for n even, Sym(n−5) × AGL(1,5), Sym(n−6) × PGL(2,5), or Sym(n−9) × PΓL(2,8). " ?

thenk u Aizenr (talk) 16:23, 14 November 2008 (UTC)


 * The wreath product, so Sym(k) wr Sym(2) has underlying set Sym(k) × Sym(k) × Sym(2), and the multiplication is ( a, b, 1 ) * ( x, y, z ) = ( ax, by, z ) and ( a, b, (1,2) ) * ( x, y, z ) = ( ay, bx, (1,2)*z ), where (1,2) is the non-identity element of Sym(2). If k is not 1, 2, or 6, then Sym(k) wr Sym(2) is the automorphism group of the direct product of two copies of the alternating group, Alt(k) × Alt(k).
 * The other direction, Sym(2) wr Sym(k), is sometimes called the "hyperoctahderal group" or the finite coxeter group of type Bk, but wikipedia might not have an article on it specifically. JackSchmidt (talk) 18:28, 14 November 2008 (UTC)

Algebra stub template
Dear Jack,

There is a (exceedingly long) discussion (that is going nowhere) about what should be the (new) algebra stub template (the sqrt(x) was removed). Currently it is a commutative diagram. Could you please participate if possible?

Topology Expert (talk) 05:50, 19 November 2008 (UTC)