Bounce Cosmology and CMB Power Suppression from Z₂ State Space Saturation in Granular Entropic Physics

We propose an effective statistical mechanism for bounce cosmology within Granular Entropic Physics (GEP), a framework in which spacetime emerges from a Planck-scale tetrahedral network with Z2 gauge field. The bounce arises from a combinatorial constraint: at Planck density, all Z2 degrees of freedom are occupied and no further field excitations can be supported. We obtain the stress-energy tensor from metric variation of an effective Z2 partition function, yielding an exact logarithmic form T_ab = g_ab[2betarho + 2flog f + (1-2f)log(1-f)] where f = rho/rho_Pl. The leading-order EFT approximation rho_eff = rho(1 - rho/rho_Pl), applied via Jacobson thermodynamics to an effective two-fluid system, yields the modified Friedmann equation (a_dot/a)^2 = (8piG/3)rho(1 - rho/rho_Pl). The Raychaudhuri equation confirms a_ddot > 0 at H = 0, establishing a non-singular bounce. The exact logarithmic model predicts a sharper approach to the bounce compared to loop quantum cosmology, with a distinct CMB signature: smooth infrared suppression C_ell^GEP = C_ell^LCDM*(1 - exp(-ell^2/ell_^2)) without oscillations, in contrast to the oscillatory LQC prediction. One emergent observational scale ell_ ~ 10-20 is introduced, qualitatively consistent with the observed Planck low-ell power deficit. The model is testable with CMB-S4 and LiteBIRD.