2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/79594We demonstrate the $(H^1,L^{1,2})$ or $(L^p,L^{p,2})$ mapping properties of several rough operators. In all cases these estimates are sharp in the sense that the Lorentz exponent 2 cannot be replaced by any lower number.26 pages, no figures, submitted to Math. AnnalenClassical Analysis and ODEs42B20text