Beyond their origin in modeling many-body quantum systems, tensor networks have emerged as a promising class of models for solving machine learning problems, notably in unsupervised generative learning. While possessing many desirable features arising from their quantum-inspired nature, tensor network generative models have previously been largely restricted to binary or categorical data, limiting their utility in real-world modeling problems. We overcome this by introducing a new family of tensor network generative models for continuous data, which are capable of learning from distributions containing continuous random variables. We develop our method in the setting of matrix product states, first deriving a universal expressivity theorem proving the ability of this model family to approximate any reasonably smooth probability density function with arbitrary precision. We then benchmark the performance of this model on several synthetic and real-world datasets, finding that the model learns and generalizes well on distributions of continuous and discrete variables. We develop methods for modeling different data domains, and introduce a trainable compression layer which is found to increase model performance given limited memory or computational resources. Overall, our methods give important theoretical and empirical evidence of the efficacy of quantum-inspired methods for the rapidly growing field of generative learning.

我们引入了一种能够学习含有连续随机变量的分布的新型张量网络生成模型，首先在矩阵乘积态的背景下推导出通用表达能力定理，证明了该模型家族能够以任意精度逼近任何充分平滑的概率密度函数；然后在几个合成和真实世界数据集上对该模型的性能进行基准测试，发现该模型在连续和离散变量的分布上学习和泛化良好；我们还开发了建模不同数据领域的方法，并引入了一个可训练的压缩层，发现在有限的内存或计算资源下，该层能够提高模型的性能。总体而言，我们的方法为量子启发式方法在生成学习这个快速发展领域的有效性提供了重要的理论和实证证据。

张量网络的连续数据生成学习