Light Universe Theory: Reinterpreting Cosmic Expansion and Inflation

This work proposes Light Universe Theory as a conceptual framework for reinterpreting cosmic expansion and inflation without assigning intrinsic physical properties to space itself. Standard cosmology explains observed redshift and large-scale structure by assuming that space dynamically expands; while mathematically successful, this assumption is rarely examined at a foundational level. In Light Universe Theory, space is treated as a relational and descriptive construct rather than a physical substance. Cosmological phenomena commonly attributed to the expansion of space are instead interpreted as consequences of light-energy dispersion and the evolution of causal structure over time. The growth of the observable universe is understood as an expansion of causal accessibility driven by the propagation of light, not as the stretching of an underlying spatial medium. Inflation theory is not rejected but reinterpreted as an early epoch of rapid light-energy density equalization across vast causal regions. This perspective preserves the empirical successes of inflation while reducing the need to invoke extraordinary physical behavior of space itself. This work introduces no new observational data or numerical models. Its aim is to reexamine the conceptual assumptions underlying modern cosmology and to offer an alternative interpretative lens through which existing observations may be understood. The paper is intended as a foundational and philosophical contribution to cosmology rather than as a finalized physical theory.