Talk:Brunn–Minkowski theorem

Untitled
"The proof of the Brunn–Minkowski theorem establishes that the function

A \mapsto [\mu (A)]^{1/n}

is concave. Thus.." The usual definition of concave (as in the link for the word concave) assumes that the function is define on some vector space, which is not the case here. Therefore I changed thus into "in the sense that"

I don't think strict concavity holds in full generality. e.g. not when A and B are in some hyperplane. I changed to convex sets, to be on the safe side but maybe it is somewhat more general. --130.133.8.114 (talk) 15:38, 5 January 2010 (UTC) Günter Rote