MMS-A15: The Entropic Spacetime Field

This paper represents an earlier stage in the development of the Entropic Spacetime Field (ESF) framework. The current reference implementation is presented in MMS-A19: The Entropic Spacetime Field: A Canonical Wave Framework for Cosmic Structure Formation 10.5281/zenodo.21433778, which supersedes the mathematical formulation described here while retaining a number of the underlying physical concepts. This keystone paper consolidates the Entropic Spacetime Field programme (ESF) developed across MMS-A1 to MMS-A14 into a single, testable framework. ESF treats spacetime as an entropy-responsive thermodynamic medium whose long-wavelength response can contribute to effective geometry while preserving General Relativity in local-test regimes. In this picture, late-time cosmic acceleration arises from an entropy–geometry coupling rather than a separate dark-energy fluid, while dark-matter phenomenology emerges from metric micro-ripples sourced by low-level baryonic processes within a persistent ripplefield layer, without requiring new particles. The paper integrates the transport specialisation introduced in later papers, including an energy-layer scaffold supporting persistent channel formation, electromagnetic-coupled transport bias and dust accumulation at long-duration nodes, offering a pathway for enhanced early structure formation. Compact objects are reframed as entropy phase transitions of the medium, replacing classical singularities with finite reconfiguration while retaining GR-consistent exterior behaviour. A constraint-first observational programme is proposed, including lensing-versus-dynamics cross-consistency tests, multi-tracer pathway alignment statistics, redshift evolution of inferred effective contributions and conservative use of CMB temperature and lensing reconstructions as fossil constraints on long-memory pathway morphology. Clear falsifiers are stated to keep the programme empirically accountable.