GeoCert: Certified Geometric AI for Reliable Forecasting

Temporal reports are increasingly emitted alongside numerical forecasts and are often interpreted as statements about the computation producing those forecasts. We formalize the resulting certification problem as three distinct stages: \emph{recoverability}, \emph{report correctness}, and \emph{functional use}. For point delays, an exact finite-sample recovery--substitutability identity ties structural discrimination and proxy prediction to the same realized shift geometry while placing them on different scales: structural evidence grows with $nη_n$, whereas the normalized predictive penalty is governed by $η_n$. A delay can therefore be statistically decisive while an alternative lag remains near-oracle. Guided by this regime, we evaluate TCN- and N-HiTS-based systems on the strict intersection of recoverable trajectories, correct reports, and near-oracle one-step predictions. Their dominant forecast dependence remains far from the reported delay under masking, finite perturbations, local Jacobians, and in-distribution conditional replacement, and the separation persists across a 100-fold forecast-loss sweep. A no-bypass factorization then provides an explicit access certificate for the final stage, while architecture-matched multi-seed, post-hoc, and gate-destruction controls identify report-coordinate access as the mechanism governing alignment. The resulting framework separates statistical evidence for \emph{what can be identified} from computational evidence for \emph{what the forecast uses}.

An unreliable language model can be made to produce reliable physical designs if the authority to assert is moved out of the model: the model proposes, and a deterministic engine alone certifies, returning certified, impossible, or unknown. We introduce Physics-Anchored Certification (PHACT), a propose-certify loop spanning five scientific domains, and identify what makes such a certificate trustworthy. A checker that accepts a model-supplied value can be forged; deriving the certified quantity from fixed inputs instead makes forgery impossible by construction. Across eighty adversarial trials spanning two models, two decoding temperatures, and a deliberately faulted engine, this contract produced zero false certifications.

Chain-of-Thought (CoT) reasoning has advanced large language models (LLMs), but outcome-based supervision leads to pervasive post-hoc rationalization, producing plausible yet unfaithful reasoning chains. Most prior faithfulness assessment methods are either unscalable, expensive, or unreliable. We propose GeoFaith, a spatio-temporal framework that leverages latent geometric structure and entropy dynamics to diagnose and enforce faithful reasoning. We develop a scalable bootstrapping pipeline expanding step-level annotations from 1k to 20k samples across four domains, train an 8B faithfulness detector outperforming GPT-5 on standard benchmarks, and design a faithfulness-aware reinforcement learning framework jointly optimizing outcome correctness, process faithfulness, and trajectory consistency. Experiments show the proposed method achieves superior performance on both faithfulness detection and downstream reasoning, producing shorter, more interpretable chains without sacrificing accuracy. Our code will be made available publicly.