  Matter isocurvature perturbations are strictly constrained from cosmic
microwave background observations. We study a sneutrino curvaton model where
both cold dark matter (CDM)/baryon isocurvature perturbations are generated. In
our model, total matter isocurvature perturbations are reduced since the
CDM/baryon isocurvature perturbations compensate for each other. We show that
this model can not only avoid the stringent observational constraints but also
suppress temperature anisotropies on large scales, which leads to improved
agreement with observations.
