Talk:Complex representation

From Wikipedia, the free encyclopedia

Mathematics Portal This article is within the scope of WikiProject Mathematics, which collaborates on articles related to mathematics.
Mathematics rating:	Stub Class	Low Priority	Field: Algebra
Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. Geometry guy 18:24, 21 May 2007 (UTC)

Wait a minute! Are you defining a real rep as a rep over a COMPLEX vector space satisfying certain reality conditions and then claiming any rep over COMPLEX vector spaces which is self-dual isn't a complex rep????????

A complex rep is a rep over a complex vector space while a real rep is a rep over a real vector space. It doesn't matter if a complex rep is self-dual. It's still a complex rep and NOT a real rep! Since you're a physicist, take the example of a Dirac spinor. It's a self-dual complex rep of the double cover of the Lorentz group which satisfies your reality conditions. But it's still a complex rep nevertheless. Or how about the Majorana spinor? It's a real rep, and to use your matrix notation in your article on real reps, it doesn't even make sense to talk of antilinear maps over it because a real rep is NOT the same thing as its complexification!!!!!!

Phys 21:58, 6 Aug 2004 (UTC)