Sohail Dimensional Stability Theory (SDST): Dynamical Spacetime Dimension and Cosmological Evolution

This paper presents Version 3.2 of the Sohail Substrate Unified Theory (SSUT),a unified framework for gravity, quantum mechanics, particle physics, and cosmology.Spacetime is modeled as a physical elastic medium whose deformation governs observable phenomena. Version 3.2 preserves the complete mathematical structure of SSUTv3.1 and introduces a Physical Structure Framework (PSF) that provides a geometricinterpretation of mass, particle structure, and gravity. The framework remains fullyconsistent with established experimental results and does not modify any previouslyderived predictions.