This work presents ψ-Lensing III: The Phantom Atlas, the first theoretical framework for mapping retentional lensing events in the 2026–2027 Euclid and Rubin observing cycles. Building on the Δψ-floor, Λψ equilibrium, and Ξ-nodes, the article establishes the full taxonomy of phantom-before-source and phantom-after-fade sequences, introduces the geometric foundations of Phantom Geometry, and defines the observational pipelines required to identify structural memory in weak-lensing datasets. The Phantom Atlas outlines the architecture, classification system, and expected coordinate map of Ξ-nodes — the metric anchors of the Retentional Regime — and provides methodological guidance for Euclid DR1 and Rubin Year 1. This work is part of the ψ-Architecture Research School (2026).
Logacheva Yulia (Mon,) studied this question.