@article{AFST_2007_6_16_1_71_0, author = {Bernard Dacorogna and Pierre Mar\'echal}, title = {Convex $\operatorname{SO}(N)\times \operatorname{SO}(n)$-invariant functions and refinements of von {Neumann{\textquoteright}s} inequality}, journal = {Annales de la Facult\'e des sciences de Toulouse : Math\'ematiques}, pages = {71--89}, publisher = {Universit\'e Paul Sabatier, Institut de Math\'ematiques}, address = {Toulouse}, volume = {Ser. 6, 16}, number = {1}, year = {2007}, doi = {10.5802/afst.1139}, mrnumber = {2325592}, language = {en}, url = {https://afst.centre-mersenne.org/articles/10.5802/afst.1139/} }