A Dual-Domain Cosmology: An Ontological Foundation for General Relativity and Quantum Field Theory

For decades, general relativity (GR) and quantum field theory (QFT) have remained conceptually incompatible — one describing gravity as geometry, the other describing particles as quantum excitations. No consensus exists on how to unite them. This paper proposes a unifying ontological interpretation that bridges this divide: spacetime is not fundamental but emerges from a deeper non-spatiotemporal quantum domain. The core thesis is that quantum entanglement is fundamental, residing in a timeless, non‑local Quantum Domain (QD). Our observable Spacetime Domain (SD) emerges as the geometric expression of entanglement transduced across a QD–SD interface governed by a maximum geometric transduction speed (MGTS), operationally measured as the invariant speed of light in vacuum. The two domains are understood as complementary aspects of a single underlying reality.Within this framework, a wide range of physical phenomena — from quantum measurement and relativistic effects to dark energy, dark matter, and cosmic evolution — are reinterpreted as manifestations of entanglement structure and its gradients. GR and QFT are not treated as fundamental theories, but as emergent descriptions of a deeper interface dynamics linking potentiality in the QD to actuality in the SD. This work does not introduce new mathematical formalism; instead, it offers an ontological foundation that invites future formal development. It provides a unified conceptual lens connecting the very large with the very small, and suggests a coherent way to understand how spacetime, matter, energy, and quantum processes arise from a single entanglement‑based substrate. Keywords: General relativity; Quantum field theory; Quantum entanglement; Quantum mechanics; Dual‑domain ontology; Spacetime emergence; Energy as entanglement; Transduction; Quantum gravity; Cosmology; Dark energy; Dark matter; Black hole information; Time dilation; Entropy.