RBS‑D Publication No. 20 — Nonlinear Coupling Dynamics in Resonance‑Based Subspace Structures

Resonance‑Based Subspace Dynamics (RBS‑D) is a 24‑part scientific framework introducing a structural interpretation of physical systems based on coupled subspaces, resonance phenomena, and nonlinear dynamics. This publication (No. 20 / 24) develops the nonlinear coupling theory of the RBS‑D framework by analyzing how interacting subspaces exchange energy, structure, and phase information under nonlinear interaction conditions. The focus lies on the formal description of coupling mechanisms governing interaction strength, synchronization effects, and emergent collective behavior in multi‑subspace systems. Within the RBS‑D framework, nonlinear coupling is described in terms of: nonlinear interaction operators between subspaces coupling‑strength dependent state evolution phase‑dependent energy and structure exchange emergent synchronization phenomena This publication extends the stability framework (P04) by introducing a generalized nonlinear coupling theory governing transitions between resonance states and dynamic regimes.