How to Fix AI Hallucination: The Nyquist Approach

By Mario Alexandre March 21, 2026 sinc-LLM Prompt Engineering

Why Current Fixes Do Not Work

The standard approach to AI hallucination is post-hoc: generate output, check it for errors, regenerate if needed. RAG (Retrieval-Augmented Generation) adds factual grounding. Fine-tuning adjusts model weights. These approaches treat symptoms, not the cause.

The sinc-LLM paper identifies the root cause: hallucination is specification aliasing caused by undersampled prompts. The fix is not better retrieval or training, it is better sampling of the specification signal.

Hallucination as Aliasing

x(t) = Σ x(nT) · sinc((t - nT) / T)

When a signal is sampled below its Nyquist rate, the reconstruction contains phantom frequencies, components that look real but were never in the original signal. This is aliasing.

When a prompt is sampled below its specification Nyquist rate (6 bands), the LLM's output contains phantom specifications, constraints, contexts, and data the model invented because you did not provide them. This is hallucination.

The parallel is not metaphorical. The mathematics are identical. And the fix is the same: sample at or above the Nyquist rate.

The Fix: 6-Band Prompt Decomposition

To eliminate hallucination at the source:

  1. Decompose every prompt into 6 specification bands: PERSONA, CONTEXT, DATA, CONSTRAINTS, FORMAT, TASK
  2. Fill every band explicitly, especially CONSTRAINTS (42.7% of output quality)
  3. Allocate ~50% of tokens to CONSTRAINTS + FORMAT
  4. Verify that no band is left for the model to guess

When all 6 bands are present, the model has nothing to hallucinate about. The specification is complete. The output matches the input because the input left no room for phantom specifications.

Evidence: 275 Observations

The sinc-LLM research measured hallucination rates across 275 prompt-response pairs:

The relationship is monotonic: each additional band reduces hallucination. But the impact is not linear, CONSTRAINTS and FORMAT have outsized effects because they are the bands most commonly left to the model's imagination.

Practical Implementation

Three ways to implement the fix:

1. Manual Decomposition

Before sending any prompt, check: does it explicitly address all 6 bands? If not, add the missing ones.

2. Auto-Scatter Tool

Use the free sinc-LLM transformer to automatically decompose raw prompts and identify missing bands.

3. Framework Integration

Integrate the sinc-LLM framework into your pipeline to enforce 6-band compliance on every prompt programmatically.

The fix is preventive, not corrective. Stop hallucination before generation, not after. Read the full paper for the mathematical proof.

Transform any prompt into 6 Nyquist-compliant bands

Try sinc-LLM Free

Real sinc-LLM Prompt Example

This is the exact JSON format that sinc-LLM uses. Paste any raw prompt at tokencalc.pro to generate one automatically.

{
  "formula": "x(t) = Σ x(nT) · sinc((t - nT) / T)",
  "T": "specification-axis",
  "fragments": [
    {
      "n": 0,
      "t": "PERSONA",
      "x": "You are a AI reliability engineer. You provide precise, evidence-based analysis with exact numbers and no hedging."
    },
    {
      "n": 1,
      "t": "CONTEXT",
      "x": "This analysis is part of a production system where accuracy determines revenue. The sinc-LLM framework identifies 6 specification bands with measured importance weights."
    },
    {
      "n": 2,
      "t": "DATA",
      "x": "Fragment importance: CONSTRAINTS=42.7%, FORMAT=26.3%, PERSONA=7.0%, CONTEXT=6.3%, DATA=3.8%, TASK=2.8%. SNR formula: 0.588 + 0.267 * G(Z1) * H(Z2) * R(Z3) * G(Z4). Production data: 275 observations, 51 agents."
    },
    {
      "n": 3,
      "t": "CONSTRAINTS",
      "x": "State facts directly. Never hedge with 'I think' or 'probably'. Use exact numbers for every claim. Do not suggest generic solutions. Every recommendation must be specific and verifiable. Include at least 3 MUST/NEVER rules specific to this task."
    },
    {
      "n": 4,
      "t": "FORMAT",
      "x": "Lead with the definitive answer. Use structured headers. Tables for comparisons. Numbered lists for sequences. Code blocks for implementations. No trailing summaries."
    },
    {
      "n": 5,
      "t": "TASK",
      "x": "Fix a medical chatbot that hallucinates drug interactions 15% of the time by adding missing specification bands"
    }
  ]
}

Install: pip install sinc-llm | GitHub | Paper