Concepts: Noise, Mitigation, and Healing

One decision primitive, evaluate_phi_trigger — is this step's change genuine dynamics, or noise? — lives in dense_evolution.mitigation.healing and gets reused by two different modules for two different kinds of data. That reuse, not a family of similar-sounding names, is the real reason "healing" and "mitigation" are easy to mix up. This page exists to make the difference un-ambiguous.

	Corrupts / heals what	Object it acts on	Module
Noise	Corrupts a real computation	A statevector, via a stochastic Kraus channel	Noise
Mitigation	Un-corrupts a noisy result	An expectation value / density matrix, extrapolated across noise strengths (Zero-Noise Extrapolation)	Mitigation
Vector Healing	Un-corrupts one bad reading in a sequence	Any (n_steps, dim) numeric sequence — a VQE/MD log, an embedding stream. Nothing quantum-specific.	IA Utils — Vector Healing

Healing (dense_evolution.mitigation.healing, still importable as dense_evolution.healing via a compatibility shim after an internal move) is the shared primitive layer the last two both call into — not a fourth thing to run on its own.

The actual code-level connection

dense_evolution.mitigation.zne's own "healing-adapted" extrapolation branch imports calculate_delta_preemp from .healing and uses it directly on the noise-strength extrapolation curve. ia_utils.vector_healing.enhanced_dense_healing_hybrid's default trigger_mode='phi' imports evaluate_phi_trigger — the same function — from dense_evolution.mitigation.healing, and applies it to whatever plain vector sequence was passed in. Same decision primitive, two call sites, two unrelated kinds of data: a quantum-noise-strength curve on one side, an arbitrary numeric log on the other.

Which page do I actually want?

• "I ran a noisy circuit and want the ideal result back" → Mitigation.
• "I have a log/trajectory/embedding sequence and one entry looks wrong" → IA Utils — Vector Healing.
• "I want to add noise to a circuit on purpose" → Noise.