The unit ball of \({\mathcal P}(^2\ell_2^2)\)
Extreme points and smooth points of the unit ball of \(P(^2 \ell_2 ^2)\) are characterised. Also, a formula is given for the norm of a 2-homogeneous polynomial on \(\ell_\infty ^2\).
scientific article; zbMATH DE number 1292438