Reference request: injective homomorphisms between unitary groups - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-21T09:48:01Z http://mathoverflow.net/feeds/question/116539 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/116539/reference-request-injective-homomorphisms-between-unitary-groups Reference request: injective homomorphisms between unitary groups Paul McKenney 2012-12-16T18:01:55Z 2012-12-16T18:01:55Z <p>Let $U(n)$ be the group of unitary $n\times n$ matrices over $\mathbb{C}$. Is there a classification of the continuous, injective group homomorphisms $U(m)\to U(n)$? If so, is there a modern account of the proof?</p>