The Cosmological Horizon as a Representability Boundary within Light Frame Cadence Theory

Abstract The cosmological horizon is commonly interpreted as a dynamical consequence of spacetime expansion. Within Light Frame Cadence Theory (LFCT), an alternative interpretation is available: the horizon corresponds to a representability limit rather than a dynamical boundary. This paper clarifies how the cosmological horizon arises in LFCT by distinguishing the sequential failure of representational modes. Mass-phase representation (TD) fails locally and in a mass-dependent manner, while spatial representability (TS) fails universally at a finite scale. Radiation (TR) remains observable at this boundary, yielding a radiation-only signature identified with the cosmic microwave background (CMB). Beyond this boundary, representation ceases. This work introduces no new data, parameters, or laws, and does not revise prior LFCT cosmological analyses. Its purpose is to make explicit a representational structure that was previously implicit, thereby fixing the interpretation of the cosmological horizon within the framework.