A Causal-Critical Universe Origin Model: Layer-Separated Single-Event Cosmology

This work proposes a conceptual cosmological model in which the origin of the universe is defined as a causal-critical fixation event rather than an energy fluctuation. The framework introduces a layer-separated structure where causality is treated as a higher-order primitive preceding time, space, and energy. The pre-universe state is modeled as a causal-connectivity multiplicity layer without defined physical quantities. When the density of admissible causal connections reaches a structural consistency bound, a necessary convergence to a single consistent causal structure occurs. This convergence is interpreted as the universe-origin event. The model presents a single-event cosmology in which the causal layer and the physical universe layer connect only once, excluding repeated universe generation and inter-universe collisions. The speed of light is interpreted as a post-fixation constraint representing the maximum causal propagation gradient rather than a primary cause. The framework is formulated as a non-mathematical conceptual cosmology emphasizing hierarchical consistency, causal primacy, and non-circular dependency structure. This paper is intended as a foundational conceptual proposal and a basis for future mathematical and theoretical formalization.