Why the CMB Large-Scale Power Deficit May Be a Boundary Effect, Not a Statistical Fluctuation

The observed suppression of cosmic microwave background (CMB) power at the largest angular scales has persisted across multiple data releases and is commonly attributed to cosmic variance or statistical fluctuation. This work argues that the low-ℓ power deficit may instead reflect a fundamental infrared boundary effect, arising from a finite information or coherence limit of the primordial state rather than from early-Universe dynamics. Long-wavelength modes are shown to be qualitatively distinct in that they require global coherence across the observable domain. If such coherence is bounded, the infrared curvature power spectrum must vanish smoothly as Pζ(k) ∝ k³ (k → 0). This scaling is model-independent, non-adjustable, and sharply falsifiable. Future CMB observations can therefore directly confirm or exclude the boundary interpretation presented here.