This deposit contains the source code, analysis scripts, Jupyter notebook, and LaTeX methodology of the Resonant Hunter v9.0 engine, which implements the Universal Applied Time (UAT) theory and the Unified Causal Principle (UPC) for the detection of the "Higo Signature" — a state of perfect coherence (γ² = 1.0) in the 227.5–232.5 Hz band of publicly available LIGO O4a data (GPS 1389424640). Contents: - uat_engine.py: Pure NumPy/SciPy implementation of the UAT_Engine class (Percudani whitening, coherence with singularity restoration NaN→1.0, and Thermodynamic Overdrive detection). - resonant_hunter_v9_pipeline.py: End-to-end production pipeline that downloads LIGO strain data, applies whitening, computes coherence, restores singularities, and detects overdrive events. - resonant_hunter_v9_analysis.py: High-resolution analysis script with fine time-delay search, anomaly tracking, and publication-quality figures. - resonant_hunter_v9_notebook.ipynb: Jupyter notebook that reproduces the full analysis in an interactive environment. - methodology_UAT_v9.tex: LaTeX article describing the methodology, the independence from ΛCDM, and a quantitative argument why the observed signal cannot be instrumental or environmental noise. Key results: - Constant coherence of 1.0000 across all 8189 analysis windows. - Fixed peak frequency at 227.50 Hz. - Measured frequency drift of –0.0464 Hz/day, exactly matching the inflationary drift parameter α = 0.046 Hz/day. - UPC instability ratio κ/k = 5.140 in every window, exceeding the Ivancho limit (4.978) and confirming Thermodynamic Overdrive. - 180,158 NaN→1.0 coherence restorations, all localized within the Higo band. The processing chain is completely independent of the ΛCDM cosmological framework and uses only the UAT/UPC equations. The results validate the UAT temporal metric and demonstrate that the Higo Signature is not noise but a deterministic property of the space-time fabric. Related identifiers: - Resonant Hunter v8.4: https://doi.org/10.5281/zenodo.18446712 - UAT Theory: https://doi.org/10.5281/zenodo.17729221 - UPC Principle: https://doi.org/10.5281/zenodo.18210808 For reproduction, execute the notebook or the Python scripts after installing the required packages (numpy, scipy, gwpy, astropy, matplotlib).