Riesz transforms on generalized Heisenberg groups and Riesz transforms associated to the CCR heat flow

Let 1 < q < [infinity]. We prove that the Riesz transforms Rk = XkL-1/2 on a generalized Heisenberg group G satisfy [fòrmula matemàtica] where K, J are respectively the dimensions of the first and second layer of the Lie algebra of G. We prove similar inequalities on Schatten spaces Sq(H), with dimension free constants, for Riesz transforms associated to commuting inner *-derivation Dk and a suitable substitute of the square function. An example is given by the derivations associated to n commuting pairs of operators (Pj, Qj) on a Hilbert space H satisfying the canonical commutation relations [Pj, Qj] = iIH