Minkowski spaces with large projection constant (Q1072053)

Let \(\lambda_ n\) be the lowest upper bound of projection constants of all \(n\)-dimensional Minkowski spaces. It is shown that \(\lambda_ 3\geq (\sqrt{5}+1)/2\), \(\lambda_ 7\geq 5/2\), \(\lambda_ n\geq c_ n\) with \(c_ n\sim (2n/e)^{1/2}\).