Silentium: A Delayed-Memory Interacting Dark Energy Model with Asymptotic ΛCDM Attractor

We present a phenomenological cosmological framework in which cosmic acceleration emerges from a delayed radiative coupling between the radiation field and a cosmological energy continuum. The model introduces a single memory timescale, τSCF, and a coupling constant, κSCF, generating an effective dynamical dark-energy component that asymptotically converges toward a ΛCDM attractor. The framework conserves energy through a closed radiation–continuum exchange, predicts a present-day equation-of-state parameter w0 = −0.672, and proposes a falsifiable observational test based on correlations between integrated radiative history and weak-lensing convergence maps. A pilot analysis using COSMOS2020 data successfully validated the technical pipeline but remains statistically underpowered for physical conclusions. The present work should be regarded as an exploratory interacting dark-energy model whose observational status remains open. Future work includes numerical integration of the delayed system, larger-scale observational tests, and implementation within standard cosmological solvers.