Inflationary cosmology is the cornerstone of the standard cosmological model, but it relies on four unjustified assumptions: an ad hoc "inflaton" field, a carefully designed potential, finely tuned initial conditions, and a separate reheating phase. Based on the fundamental axioms of UD theory, this paper demonstrates that inflation is a natural consequence of the asymmetry between the two fundamental attributes U and D. The U attribute manifests directly as space—expansion is immediate and unhindered. The D attribute desires to condense into matter, but this condensation is mediated by DU (quantum fluctuations) and governed by the fine structure constant α. Since α ≈ 1/137 is small, condensation is inefficient and delayed. Consequently, the Hubble parameter H = k·E/C is enormous—this is inflation. Inflation ends naturally when C grows to become comparable to E, requiring no additional assumptions. A direct consequence is that the local expansion rate depends on the local matter density: H = k (1-C) /C implies that matter-rich regions expand slower, while voids expand faster, providing a natural explanation for the Hubble tension. The primordial perturbations arise from quantum fluctuations of DU. Using the UD-derived physical inputs—the identity of the inflaton (DU) and the de Sitter background (E ≫ C) —the standard calculation yields the spectral index nₛ = 1 - 2/N. With N = 60, this gives nₛ = 0. 9667, in excellent agreement with the Planck 2018 measurement 0. 9649 ± 0. 0042 (0. 19% error). Tensor perturbations arise from UU fluctuations. By the shared U nature of UU and DU, their fluctuation amplitudes are comparable, yielding r ≈ 3. 8 × 10^-4, consistent with current bounds. Where standard inflation assumes, UD theory derives. The "necessary hypotheses" of the inflaton potential and reheating mechanism are completely eliminated.
Dan Zhu (2026) studied this question.