Quantum Information Copy Time (QICT) Cosmology with an Open-System Complex-Phase Dark Sector: Rigorous Foundations and Global Background-Level Feasibility Tests Toward H0 and S8 Alleviation

We develop a falsifiable effective framework in which the infrared scale entering holographic dark energy is defined operationally by a quantum-information copying time. For a physical separation L at cosmic time t, the copy time τcopy(L,t) is the time required to replicate a minimal unit of quantum information across that separation. The copy horizon Lcopy(t) is fixed locally by τcopy(Lcopy,t) = ξ/H(t), with ξ= O(1). Combining this operational infrared scale with the Cohen–Kaplan–Nelson gravitational-collapse bound motivates an energy density ρQ(t) = 3κM2 Plc2 Q(t)/L2 copy(t) and promotes “saturation” to a one-sided falsifiable inequality 0