The Price of Freedom: Exploring Tradeoffs in Equivariant Tensor Products with Spherical Signals

26 Sept 2024 (modified: 27 Nov 2024)ICLR 2025 Conference Withdrawn SubmissionEveryoneRevisionsBibTeXCC BY 4.0
Keywords: equivariance, tensor product, spherical harmonics, vector spherical harmonics, spherical signals, benchmarking, asymptotics
TL;DR: We propose a new vector signal tensor product and show how to compare different tensor products which have different expressivity.
Abstract: $E(3)$-equivariant neural networks have demonstrated success across a wide range of 3D modelling tasks. A fundamental operation in these networks is the tensor product, which interacts two geometric features in an equivariant manner to create new features. Due to the high computational complexity of the tensor product, significant effort has been invested to optimize the runtime of this operation. \citet{gaunt} recently proposed the Gaunt tensor product (GTP) which promises a significant speedup over the naive implementation of the tensor product. However, this method is unable to perform antisymmetric operations which are crucial for tasks involving chirality. In this work, we introduce vector signal tensor product (VSTP) to solve this issue and show how it generalizes to a class of irrep signal tensor products (ISTPs). Finally, we investigate why these tensor products are faster. We find most of the speedup comes at the price of expressivity. Further, we microbenchmarked the various tensor products and find that the theoretical runtime guarantees may differ wildly from empirical performance, demonstrating the need for careful application-specific benchmarking. Our code is linked \href{https://anonymous.4open.science/r/vector-spherical-harmonics-1231/}{here}.
Primary Area: learning on graphs and other geometries & topologies
Code Of Ethics: I acknowledge that I and all co-authors of this work have read and commit to adhering to the ICLR Code of Ethics.
Submission Guidelines: I certify that this submission complies with the submission instructions as described on https://iclr.cc/Conferences/2025/AuthorGuide.
Reciprocal Reviewing: I understand the reciprocal reviewing requirement as described on https://iclr.cc/Conferences/2025/CallForPapers. If none of the authors are registered as a reviewer, it may result in a desk rejection at the discretion of the program chairs. To request an exception, please complete this form at https://forms.gle/Huojr6VjkFxiQsUp6.
Anonymous Url: I certify that there is no URL (e.g., github page) that could be used to find authors’ identity.
No Acknowledgement Section: I certify that there is no acknowledgement section in this submission for double blind review.
Submission Number: 7672
Loading

OpenReview is a long-term project to advance science through improved peer review with legal nonprofit status. We gratefully acknowledge the support of the OpenReview Sponsors. © 2025 OpenReview