Capacity‑Induced Classical Emergence: A Finite‑Information Approach to the Quantum Measurement Problem

This work proposes a finite‑capacity reformulation of the quantum measurement problem within the Symbolic Field Information Theory (SFIT) and F‑CDT framework. Instead of modifying the Schrödinger equation or postulating an ad hoc collapse, it assumes that the pre‑geometric substrate of quantum spacetime has a finite symbolic resolution capacity ⁡Cₘₐₓ per causal correlation volume. Quantum evolution remains unitary at the substrate level, while effective classicality emerges through coarse‑graining over histories whose pairwise distinguishability cost C[x,x′] exceeds ⁡Cₘₐₓ. This is implemented via a pairwise capacity filter acting on the Feynman–Vernon influence functional, yielding sigmoidal, threshold‑like suppression of interference with a hard structural cutoff of tails, rather than the purely exponential decay of standard decoherence. The paper develops the formalism, connects Cₘₐₓ to causal‑diamond area bounds for relativistic covariance, and outlines an experimental protocol with levitated nanoparticles to distinguish SFIT from environmental decoherence and GRW/CSL collapse models. The framework is explicitly programmatic: complete positivity of the reduced dynamics and derivation of Cₘₐₓ from the microscopic F‑CDT substrate are identified as central open problems. A finite‑information, causal‑diamond–based proposal where a substrate capacity bound suppresses interference and yields classical outcomes without modifying the Schrödinger equation.