Cosmological Data Compression: Entropy Production, Horizon Storage, and the Temporal Structure of the Universe

We present the Cosmological Data Compression Model (CDCM), a quantitative framework in which cosmic entropy production is interpreted as a time-dependent compression process that serializes transient physical states into a permanent holographic archive defined by the cosmological horizon. Using standard ΛCDM expansion history and established entropy inventories, we define a compression fraction and a compression efficiency that couple entropy production to horizon growth. We show that the compression efficiency is not constant, but instead peaks during the epoch of maximal cosmic structure formation and supermassive black hole accretion (�), and declines at both early times (when structure is absent) and late times (during dark-energy domination). At all observable epochs, the universe remains far below its holographic storage bound, implying that cosmic evolution proceeds as an unsaturated archival process. The model does not modify general relativity or introduce new fundamental forces. Instead, it provides a falsifiable interpretive layer linking entropy production, large-scale structure, and cosmological horizons. CDCM makes clear empirical predictions for the redshift evolution of compression efficiency and its correlation with observed quasar activity and black hole growth.