A Structural Model of PBH Evaporation and Gamma-Ray Suppression

Description This record provides the manuscript “A Structural Model of PBH Evaporation and Gamma-Ray Suppression”, which develops a minimal structural framework for the late-time evaporation of primordial black holes (PBHs). The model describes PBH evolution as the balance between a quantum spreading tendency and a gravitational contracting tendency. This competition produces an effective temperature that reaches a maximum and then decreases toward zero as the PBH mass approaches a finite core scale. The resulting temperature behavior leads to several observational consequences: a suppressed high-energy tail in the gamma‑ray spectrum, the absence of a terminal burst, a characteristic cutoff in the 30–300 GeV band, a broken MeV–GeV spectrum, and a non‑flaring light curve. These signatures fall within the sensitivity ranges of upcoming gamma‑ray missions such as CTA and AMEGO‑X. The framework offers a structurally motivated explanation for the long‑standing non‑detection of high‑energy PBH bursts and provides testable predictions relevant to near‑future observations. No new data were generated for this study, and the manuscript is provided for open access archiving and citation.