Information-Theoretic Cosmology: A Survey and Prospectus

This paper surveys the foundational results connecting information theory, quantum entanglement, and horizon thermodynamics to the large-scale structure and dynamics of the universe, and argues that they constitute the basis of a coherent field: information-theoretic cosmology. The survey traces the lineage from Bekenstein's area-entropy relation (1973) and Hawking radiation (1975) through Jacobson's thermodynamic derivation of the Einstein equations (1995), the Ryu–Takayanagi formula (2006), and the emergent spacetime program (Van Raamsdonk 2010, ER=EPR, tensor networks) to recent information-theoretic treatments of the cosmological constant problem, black hole evaporation endpoints, quantum cosmology, and the multiverse. These results currently reside in separate subfields -- gr-qc, hep-th, quant-ph, astro-ph.CO -- without a shared identity or organizing framework. The paper identifies the common principles, catalogs seventeen open problems across four categories, and maps the cross-connections between them. Recent developments surveyed include: the Landauer identification, which applies Landauer's principle to irreversible correlation transfer at the cosmological horizon, yielding the parameter-free prediction ΩΛ = ln 2 ≈ 0.6931 (consistent with Planck 2018 to 0.2%); the flow equilibrium mechanism, which maintains this density through a steady-state population of decohered vacuum modes; the minimal closure argument for the black hole evaporation endpoint; the reinterpretation of Hawking radiation as Landauer energy cost; and the subsystem-to-cosmology distinction for Planck-scale expansion. A cross-connection table demonstrates that the program's open problems form an interconnected web in which progress on any one question constrains several others -- the structural signature of a unified field. The paper proposes the name "information-theoretic cosmology" for this program and argues that the scattered community working on these questions would benefit from a shared arena.