We present the group equivariant conditional neural process (EquivCNP), a meta-learning method with permutation invariance in a data set as in conventional conditional neural processes (CNPs), and it also has transformation equivariance in data space. Incorporating group equivariance, such as rotation and scaling equivariance, provides a way to consider the symmetry of real-world data. We give a decomposition theorem for permutation-invariant and group-equivariant maps, which leads us to construct EquivCNPs with an infinite-dimensional latent space to handle group symmetries. In this paper, we build architecture using Lie group convolutional layers for practical implementation. We show that EquivCNP with translation equivariance achieves comparable performance to conventional CNPs in a 1D regression task. Moreover, we demonstrate that incorporating an appropriate Lie group equivariance, EquivCNP is capable of zero-shot generalization for an image-completion task by selecting an appropriate Lie group equivariance.

本文提出了一种具有置换不变性和数据空间变换等变性的元学习方法 EQuivCNP，其建立在数据集的置换不变性与常规条件神经过程（CNPs）相同，且具有转换等变性；结合群等变性提供了考虑现实世界中的数据对称性的方式，并使用李群卷积层构建体系结构进行实际实现，EquivCNP 在具有等变性的情况下能够实现零样本泛化。

群等变条件神经过程