In plain words: Softmax attention may work not because it turns scores into probabilities, but because it keeps the attention matrix's overall size in check, which steadies training. Polynomial activations that do the same job matched softmax's performance, even without positive, normalized, or sparse weights.
Abstract · Rethinking Attention: Polynomial Alternatives to Softmax in Transformers
This paper questions whether the strong performance of softmax attention in transformers stems from producing a probability distribution over inputs. Instead, we argue that softmax's effectiveness lies in its implicit regularization of the Frobenius norm of the attention matrix, which stabilizes training. Motivated by this, we explore alternative activations, specifically polynomials, that achieve a similar regularization effect. Our theoretical analysis shows that certain polynomials can serve as effective substitutes for softmax, achieving strong performance across transformer applications despite violating softmax's typical properties of positivity, normalization, and sparsity. Extensive experiments support these findings, offering a new perspective on attention mechanisms.
Hemanth Saratchandran, Jianqiao Zheng, Yiping Ji, Wenbo Zhang, Simon Lucey
arXiv:2410.18613 · cs.LG, cs.CV, stat.ML · submitted Oct 24, 2024 · updated Mar 13, 2026
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