Spectral Suppression of Asymptotic States in Supersymmetric QFT on de Sitter Backgrounds

Abstract: We investigate the fate of asymptotic particle states in supersymmetric quantum field theories on de Sitter backgrounds, distinguishing algebraic field content from localized LSZ-like excitations. We study how long-wavelength gravitational fluctuations may suppress pole residues and redistribute spectral weight from isolated contributions toward continuum sectors. The analysis is formulated within a Kallen-Lehmann spectral framework and is intended as a structural infrared mechanism rather than a non-perturbative proof of de Sitter quantum gravity. The paper develops three connected levels. First, we analyze residue suppression in a quasi-de Sitter setting and its possible transmission through Yukawa and gravitational interactions. Second, we formulate the spectral decomposition as a map between the full field-theoretic spectrum and the observable particle sector. Third, we examine a conditional cosmological realization of redistributed spectral weight, including possible effects on expansion, structure growth, and lensing. This cosmological layer is a downstream phenomenological test and is not used as evidence that pole loss has occurred. In the current MCMC analysis we find S8 approximately 0.803 and, when the smooth fraction is varied, fS8 = 0.0025 +/- 0.0017, consistent with the benchmark value 0.00262. These results test the internal consistency of the proposed realization but do not establish the dark-sector assignment or the underlying infrared mechanism.