RMB — Core Architecture: Reaction-Based Gravity as a Matter–Motion–Space Framework

This work presents the core conceptual architecture of the Reaction-based Model of Gravity (RMB).RMB is introduced as an autonomous framework in which gravity emerges as the dynamic reaction of physical space to matter density and organized motion, with rotation and vorticity treated as co-primary sources alongside conventional stress–energy. The paper focuses on ontological structure, source hierarchy, well-defined reduction limits, and a schematic field representation, while remaining intentionally pre-formal and pre-Lagrangian.It serves as the conceptual foundation for forthcoming quantitative developments and empirical tests.