2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/226380It is well known that R^N has subspaces of dimension proportional to N on which the \ell_1 norm is equivalent to the \ell_2 norm; however, no explicit constructions are known. Extending earlier work by Artstein--Avidan and Milman, we prove that such a subspace can be generated using O(N) random bits.16 pages; minor changes in the introduction to make it more accessible to both Math and CS readersFunctional AnalysisComputational ComplexityMetric Geometrytext