The paper investigates quantum decoherence in a class of models that interpolate between expanding (inflation) and contracting (ekpyrosis) universes. For models resulting in a scale-invariant power spectrum, the authors find that ekpyrotic universes lead to complete decoherence of the curvature perturbation before the bounce, in contrast to inflationary scenarios where recoherence has been observed. They compute the purity for various coupling sizes and study its perturbative behavior, noting that late-time breakdown often occurs. To address this, they develop a late-time purity resummation that captures the exact evolution with high accuracy while maintaining analytical control. The cosmological background plays a crucial role in the decoupling of heavy fields during inflation and alternatives. The study uses two-field models admitting scaling solutions to explore the impact of different background evolutions on the dynamics of cosmological inhomogeneities. The results highlight the efficiency of decoherence in ekpyrotic phases and provide insights into the scaling and asymptotic behavior of the purity.The paper investigates quantum decoherence in a class of models that interpolate between expanding (inflation) and contracting (ekpyrosis) universes. For models resulting in a scale-invariant power spectrum, the authors find that ekpyrotic universes lead to complete decoherence of the curvature perturbation before the bounce, in contrast to inflationary scenarios where recoherence has been observed. They compute the purity for various coupling sizes and study its perturbative behavior, noting that late-time breakdown often occurs. To address this, they develop a late-time purity resummation that captures the exact evolution with high accuracy while maintaining analytical control. The cosmological background plays a crucial role in the decoupling of heavy fields during inflation and alternatives. The study uses two-field models admitting scaling solutions to explore the impact of different background evolutions on the dynamics of cosmological inhomogeneities. The results highlight the efficiency of decoherence in ekpyrotic phases and provide insights into the scaling and asymptotic behavior of the purity.