Structural Differentiation Cosmology (SDC): An Irreversible Universe Model Based on the Impossibility of Nothingness

This paper presents Structural Differentiation Cosmology (SDC), a theoretical frameworkbased on the premise that “nothingness cannot exist.”The universe is modeled as a closed system without external reference, where cosmic evolutionis described not as the creation of new entities but as irreversible internal reconfigurationof existing structure. A central variable, structural density C(t), represents the degree of internal differentiation.Cosmic expansion and acceleration are interpreted as observational projections of changesin structural density rather than physical expansion of space.This framework offers an alternative interpretation of dark-energy-like phenomenawithout introducing additional physical components.