Emergent Backreaction Cosmology from Defect Lattice Dynamics: A Closed Microscopic Origin of Dark Energy via Variance Dynamics

We present a fully closed discrete cosmological framework in whichdark energy emerges as a dynamical fixed point of defect-driven spacetime fluctuations. The fundamental degrees of freedom are latticedefects with density ρd(x,t).We show that:• local expansion H(x,t) is linearly sourced by defect fluctuations,• cosmological backreaction arises as variance of the expansionfield,• the backreaction term Q(t) obeys a closed dynamical equation,• and the system flows to a stable attractor producing ΩΛ ≈ 0.68.Dark energy is therefore not fundamental, but an emergent statistical equilibrium of microscopic spacetime dynamics.