This paper explores the potential connection between the ABC conjecture innumber theory and physical phenomena in the early universe. Based on the axiomatic assumptions of ”the universe as an information processing system” and”information conservation” and ”computability”, we reinterpret the arithmetic inequality implied by the ABC conjecture as an efficiency constraint on the ”additive” synthesis processes in the cosmic information flow. This constraint is mappedto a suppression of specific non-Gaussian signals in the cosmic microwave background (CMB) radiation: namely, on collinear triangular configurations satisfyingthe scalar wavenumber addition relation (k1+k2 = k3), the non-Gaussian amplitudeshould exhibit a characteristic exponential decay at high wavenumbers (corresponding to small angular scales). We performed the first test of this prediction usingPlanck 2018 satellite data and observed a suppression signal qualitatively consistentwith the model in the multipole range ℓ > 500, with a global significance of approximately 2.9σ. Further simulation analysis indicates that next-generation CMB-S4experiments will have the capability to conduct a decisive test of this signal. Thisstudy provides a new, operational and falsifiable path for testing the physical relevance of fundamental mathematical structures through cosmological observations.