Time as Index: A Structural Resolution of the Quantum Eraser Problem

Quantum eraser experiments are frequently interpreted as providing evidence for the retroactive erasure of recorded information, seemingly implying a modification of the past. In this paper, we demonstrate that within the "Time as Index" (TASI) framework, quantum eraser phenomena do not necessitate such retrocausal interpretations. By defining time as the irreversible indexing of distinctions into a trace space \mathcal{T}, the framework rigorously differentiates between non-indexed (reversible) correlations and newly indexed histories. The analysis decomposes the problem into two exhaustive and mutually exclusive cases: • Case I: The information was erasable because it was never indexed, meaning no irreversible trace was formed and thus no "past" existed to be modified. • Case II: The act of erasure itself produces an irreversible trace, constituting a new indexing event or "past succession" rather than a modification of an existing history. This document provides a structural resolution to the apparent paradoxes in both standard and delayed-choice quantum erasers. It further includes two reviewer-style commentaries that evaluate the consistency of the argument and analyze how the delayed-choice variant serves to sharpen the criterion for indexing boundaries.