Goodfire AI researchers identify shape-rotating calculator in language models

- Goodfire AI researchers identified an internal mechanism in large language models that performs addition and related operations by rotating shapes in high-dimensional neural space. The reusable structure interfaces with Fourier features and reads from geometric representations learned during training. It extends to other computational tasks and builds on a 2023 arXiv paper on modular addition circuits. Released visualizations display shifting activation clusters in scatter plots.