Local Representability in Finite-Capacity Causal Horizons: A Phenomenological Approach to Effective Cosmology a Testable Framework for Holographic Saturation The Effective 17% Density Excess, and the Geometric–Informational Partition

Abstract

The holographic principle suggests that the physically accessible information contained inside a causal region may ultimately be constrained by the entropy associated with its boundary. Motivated by this idea, we investigate a phenomenological framework in which causal horizons possess a finite effective information capacity that limits the local semiclassical representability of bulk degrees of freedom while preserving global unitary evolution.
The proposed framework does not modify microscopic quantum dynamics. Instead, it assumes that as a causal horizon approaches an effective saturation regime, the reconstruction of bulk physics by a local semiclassical observer gradually becomes incomplete, whereas the complete physical state remains encoded globally through nonlocal quantum correlations.
An effective entropy–area response density is introduced as a phenomenological quantity describing the local informational cost associated with representing bulk excitations on a causal boundary. A complementary geometric–informational partition is then postulated as a normalization hypothesis motivated by spherical geometry.
The framework is further compared with the observational discrepancy between early- and late-time determinations of the Hubble parameter, expressed as an effective density excess of approximately 17%. This observational quantity is not identified with the geometric normalization itself, but rather provides a phenomenological scale against which the proposed mechanism may eventually be tested.
The present work therefore introduces a falsifiable theoretical program rather than a complete cosmological model. Its principal objective is to establish a mathematically consistent framework from which microscopic horizon dynamics may later derive quantitative corrections to cosmological evolution.