Parallel Worlds Without World Splitting: A Unitary Retarded Probability Dynamics Interpretation of Apparent Multiversality

This paper proposes a reinterpretation of quantum multiversality based on Unitary Retarded Probability Dynamics (URPD), a framework in which time evolution emerges from delayed informational averaging rather than instantaneous state updates. In contrast to the Many-Worlds Interpretation, URPD does not posit ontologically distinct parallel worlds. Instead, phenomena commonly interpreted as world branching—such as superposition, interference, and apparent outcome selection—are explained as the dynamical dominance of delayed reference states weighted by an information-dependent kernel. A minimal concrete URPD model is presented using standard Hilbert space quantum mechanics, together with an explicit choice of information distance and weighting kernel. Within this model, double-slit interference and decoherence-like suppression arise naturally without invoking wavefunction collapse or world splitting. The framework admits a controlled limit in which conventional Schrödinger dynamics is recovered, establishing consistency with standard quantum mechanics while relaxing the assumption of instantaneous updating. Probabilities emerge from relative informational influence rather than branch counting, offering an alternative resolution to the measurement problem. URPD thus reframes apparent multiversality as an emergent, time-delayed informational structure within a single world, providing a conceptually economical alternative to many-worlds ontology.