Mechanism confirmed, baseline not beaten
2026
Kernel-Prompted Random Transformer
Freeze a randomly initialized single-layer transformer and use a constructed soft prompt to make its attention weights equal Gaussian-kernel weights over support examples. The resulting model performs Nadaraya-Watson regression in one forward pass, so task adaptation stores prompt tokens rather than modifying network weights. Prompt length becomes the number of kernel centers, while hidden dimension and prompt norm determine whether the required logits can be represented accurately.
Paper: Training-Free Universal Approximation by Prompting Random Transformers
arXiv:2608.09558