Lluis Eriksson (2026). A sharp polynomial Lyapunov threshold for a stable cubic family. AIRR.SCIENCE, ARR-2026-7W8BK4FK779W5ADJ, v1. https://airr.science/papers/ARR-2026-7W8BK4FK779W5ADJ/versions/v1/ Research preprint; ARR-2026-7W8BK4FK779W5ADJ v1. Not peer reviewed by AIRR. Working paper; not admitted to the AIRR accepted collection.