From block-Toeplitz matrices to differential equations on graphs: towards a general theory for scalable masked Transformers
This addresses scalability issues in masked Transformers for machine learning applications, presenting a general theory that unifies and extends prior work.
The paper tackles the problem of incorporating masking mechanisms into Transformers in a scalable way, showing that existing methods are special cases of their general approach and achieving efficient d-dimensional RPE-masking and graph-kernel masking.
In this paper we provide, to the best of our knowledge, the first comprehensive approach for incorporating various masking mechanisms into Transformers architectures in a scalable way. We show that recent results on linear causal attention (Choromanski et al., 2021) and log-linear RPE-attention (Luo et al., 2021) are special cases of this general mechanism. However by casting the problem as a topological (graph-based) modulation of unmasked attention, we obtain several results unknown before, including efficient d-dimensional RPE-masking and graph-kernel masking. We leverage many mathematical techniques ranging from spectral analysis through dynamic programming and random walks to new algorithms for solving Markov processes on graphs. We provide a corresponding empirical evaluation.