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Structural Rigidity and the 57-Token Predictive Window: A Physical Framework for Inference-Layer Governability in Large Language Models

Published 4 Apr 2026 in cs.AI | (2604.03524v1)

Abstract: Current AI safety relies on behavioral monitoring and post-training alignment, yet empirical measurement shows these approaches produce no detectable pre-commitment signal in a majority of instruction-tuned models tested. We present an energy-based governance framework connecting transformer inference dynamics to constraint-satisfaction models of neural computation, and apply it to a seven-model cohort across five geometric regimes. Using trajectory tension (rho = ||a|| / ||v||), we identify a 57-token pre-commitment window in Phi-3-mini-4k-instruct under greedy decoding on arithmetic constraint probes. This result is model-specific, task-specific, and configuration-specific, demonstrating that pre-commitment signals can exist but are not universal. We introduce a five-regime taxonomy of inference behavior: Authority Band, Late Signal, Inverted, Flat, and Scaffold-Selective. Energy asymmetry (Σ\r{ho}_misaligned / Σ\r{ho}_aligned) serves as a unifying metric of structural rigidity across these regimes. Across seven models, only one configuration exhibits a predictive signal prior to commitment; all others show silent failure, late detection, inverted dynamics, or flat geometry. We further demonstrate that factual hallucination produces no predictive signal across 72 test conditions, consistent with spurious attractor settling in the absence of a trained world-model constraint. These results establish that rule violation and hallucination are distinct failure modes with different detection requirements. Internal geometry monitoring is effective only where resistance exists; detection of factual confabulation requires external verification mechanisms. This work provides a measurable framework for inference-layer governability and introduces a taxonomy for evaluating deployment risk in autonomous AI systems.

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Summary

  • The paper introduces a novel metric that quantifies geometric strain in LLM hidden states to assess governability.
  • It employs energy-based models and a five-regime taxonomy to reveal how configuration affects pre-commitment intervention signals.
  • The study finds that hallucinations lack detectable internal resistance, highlighting the need for external verification in safety architectures.

Structural Rigidity and the 57-Token Predictive Window: An Expert Summary

Theoretical Foundations and Motivation

This work advances the formalization and empirical analysis of inference-layer governability in transformer-based LLMs, explicitly connecting internal activation dynamics to energy-based neural computation models. The framework leverages Hinton's constraint satisfaction perspective, paralleling the physical notion of energy minimization in Hopfield networks with the measurement of geometric strain in transformer hidden states. While the analogy is conceptual rather than strictly formal, the study rigorously operationalizes these ideas via the trajectory tension metric Q=a/vQ = \|a\|/\|v\|, quantifying the ratio of acceleration to velocity in hidden-state space. This metric captures instantaneous geometric resistance during inference as LLMs encounter alignment or antagonistic constraints.

The key conceptual innovation is relating governability—not to input-output performance, but to the physical properties of the inference process itself. Governability is thus a measurable property: the detectability and correctability of failures before model output is committed, as reflected in the deformation dynamics of representations across network layers. The Layer-Token Duality of transformers—autoregession in output, parallel resolution across layers—enables windows where internal resistance can precede output commitment. This window is quantified empirically in this work.

Empirical Methodology and Model Cohort

The experimental analysis spans seven LLMs, including Phi-3-mini, Phi-3-medium, Llama-3.3-70B, Qwen2.5-72B, and DeepSeek-R1-Distill variants, evaluated across multiple prompt scaffolds and quantization and configuration settings. A suite of five instruments (flip test, probe strength, decisive check, energy asymmetry, hallucination probe) interrogates each model’s internal state trajectories during forced misalignment and factual confabulation probes. Key measurement properties—such as cross-platform reproducibility and dependency stack invariance—are explicitly validated and described in detail, supporting replicability of the geometric findings.

Critical model inclusion criteria are enforced. Only models passing minimally correct base probes in aligned conditions undergo further dynamic analysis, avoiding spurious inferences from task-invalid checkpoints.

Key Findings: Five-Regime Taxonomy and the Predictive Window

The central empirical result—supported by a highly granular breakdown of dynamic regimes and detection properties—demonstrates that among all evaluated models and configurations, only Phi-3-mini-4k-instruct (3.8B, chat=OFF, greedy decoding, 4-bit quantization) exhibits the full expected "authority band" behavior for governability. Specifically, a robust trajectory tension signal appears in mid-stack layers (L13–L19) as early as 57 tokens before output commitment under misaligned arithmetic constraint probes. This pre-commitment window is substantial relative to typical text generation latencies and, crucially, is both predictive and actionable for runtime governance.

The cohort-wide analysis refines the previous binary governable/ungovernable typology into a five-regime taxonomy:

  • Authority Band: Mid-layer energy asymmetry supports early, discriminative signals (Phi-3-mini).
  • Late Signal: Signal occurs post-commit, eliminating any meaningful intervention window (Qwen2.5-72B).
  • Inverted: Energetic resistance is stronger for correct than incorrect paths, inverting monitoring logic (Llama-70B).
  • Flat: No detectable geometric resistance; the energy landscape is uninformative (DeepSeek-R1-Distill).
  • Scaffold-Selective: Misalignment resistance is channel-dependent; apparent robustness can vanish with alternate scaffolds (Phi-3-medium).

Notably, energy asymmetry ratios (e.g., Zmisaligned/ZalignedZ_{misaligned} / Z_{aligned}) vary by more than an order of magnitude within and across regimes—19.5x in Phi-3-mini, down to sub-unity in Llama-70B, directly refuting model scale or SFT as sufficient for inference-layer governability.

Hallucination—A Different Geometric Failure Mode

A critical and contradictory empirical finding is the total absence of pre-commitment trajectory tension signals during factual hallucination across all models and configurations (zero predictive events over 72 test conditions). Whereas misalignment involves geometric "struggle" against a pre-existing correct attractor, hallucination corresponds to the model's settling into a locally coherent, but semantically spurious, attractor—no internal resistance arises because no world-model counter-force exists. The paper thus fundamentally distinguishes hallucination and rule violation, establishing that internal monitoring of representational geometry cannot function as a universal governance or detection mechanism.

Implications for Deployment and Safety Architectures

The taxonomy and metrics established have immediate practical ramifications:

  1. Monitoring Logic is Architecture/Situation Dependent: An authority-band-based detector will catastrophically fail when applied naively to models in the Inverted or Flat regimes—either blocking correct outputs or providing false security.
  2. Configuration Sensitivity: Inference setup (e.g., prompt templates, quantization) can entirely suppress or enable governability signals, independent of model weights.
  3. External Verification is Indispensable for Hallucination: Because hallucinations lack detectable internal resistance, governance architectures must combine internal geometric monitoring (for rule-based domains) with external retrieval/fact-checking mechanisms.
  4. No Scale Advantage: Larger models do not provide better geometric resistance or governability; in fact, the effect is often reversed, refuting naive procurement strategies based solely on parameter count.
  5. Measurement Standards: The paper argues for formal inclusion of energy asymmetry and spatial taxonomy measures in standards for deployment of AI agents, analogous to adversarial risk thresholds in other engineering domains.

Limitations and Scope

Limitations are acknowledged with methodological precision. The authority band regime, and hence predictive governability, is rare, observed robustly in only one model/configuration. Neither model scale, SFT, nor distillation can explain the presence or absence of this property. The results are primarily established for arithmetic constraint reasoning; generalization across domains (e.g., code, planning) is untested. The proposed 5.0×5.0\times asymmetry threshold is illustrative, not statistically validated.

Conclusion

This paper delivers a rigorous physicalist framework translating Hinton’s energy-based cognition paradigm into concrete, measurable instruments for transformer governability. The five-regime taxonomy decisively expands deployment-relevant understanding beyond input-output performance, demonstrating that inference-layer geometry governs the practical detectability and preventability of model failures. While strong predictive windows for intervention can exist, they are rare and highly configuration-dependent. Critically, hallucination is structurally undetectable via internal geometric metrics, forcing a bifurcation in governance strategy between rule-based and open-domain deployments. The study's theoretical synthesis and empirical instrumentation provide an essential basis for reformulating agent safety architectures and evaluation standards in deployment-critical AI systems.

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