Dvoretzky 1961: every n-dim normed space has subspace of dimension d ~ log n that is (1+eps)-isomorphic to Euclidean ball; Milman 1971 proof via concentration on sphere.
Dvoretzky 1961: every n-dim normed space has subspace of dimension d ~ log n that is (1+eps)-isomorphic to Euclidean ball; Milman 1971 proof via concentration on sphere.