TY - JOUR Y1 - 2010/07// A1 - Saracco, Fabio A1 - Pietroni, M. A1 - Tetradis, N. A1 - Pettorino, V. A1 - Robbers, G. PB - American Physical Society VL - 82 SN - 1550-7998 UR - http://link.aps.org/doi/10.1103/PhysRevD.82.023528 JF - Physical Review D N2 - We consider cosmologies in which a dark-energy scalar field interacts with cold dark matter. The growth of perturbations is followed beyond the linear level by means of the time-renormalization-group method, which is extended to describe a multicomponent matter sector. Even in the absence of the extra interaction, a scale-dependent bias is generated as a consequence of the different initial conditions for baryons and dark matter after decoupling. The effect is enhanced significantly by the extra coupling and can be at the 2%?3% level in the range of scales of baryonic acoustic oscillations. We compare our results with N-body simulations, finding very good agreement. AV - public TI - Nonlinear matter spectra in coupled quintessence ID - eprints2905 ER -