arXiv AI

Tensor network representations of discrete maximum entropy distributions via mean polytopes

arXiv Machine Learning
Sep 4

Parameterised graph theory for tensor networks: entanglement rerouting, structural simplification, and agnostic tomography

The paper applies parameterised graph theory to tensor networks, showing that cutwidth and tree‑cutwidth bound the bond‑dimension overhead needed to represent a tensor‑network state as a matrix product state or tree tensor network. It derives graph‑dependent upper bounds on the sample and computational complexity of tensor‑network tomography, introducing a new graph parameter called learning complexity. Finally, it extends the framework to an agnostic learner that approximates any state with a tensor‑network state of given bond dimension, providing explicit graph‑dependent complexity bounds.

By Matthias C. Caro, Natalie McHugh, Sergii Strelchuk
arXiv Machine Learning
Oct 28

On the Architectural Complexity of Neural Networks

The paper presents a unified theoretical framework for analyzing and constructing deep neural networks by explicitly modeling tensor operations, which are often abstracted in existing theories. This framework allows researchers to study how architectural complexity has evolved over the past 40 years and to automatically generate new architectures using novel tensor operations. The authors also release a dataset of over 3,000 higher‑complexity architectures that have not yet been explored, providing a resource for future research.

By Nicholas J. Cooper, Fran\c{c}ois G. Meyer, Michael L. Roberts, Carlos Zapata-Carratal\'a, Lijun Chen, Danna Gurari
arXiv Machine Learning
Sep 23

Riemannian Optimization on Tree Tensor Networks with Application in Machine Learning

The paper presents a formal analysis of the quotient geometry of tree tensor networks (TTNs) and introduces efficient first- and second-order optimization algorithms that leverage this geometry. It also develops a backpropagation method for training TTNs in a kernel learning context. Numerical experiments on a digit classification task demonstrate a tradeoff between two horizontal distributions: one provides clearer geometric insights, while the other yields more efficient algorithms.

By Marius Willner, Marco Trenti, Dirk Lebiedz
arXiv Machine Learning
Oct 12

The Expressive Power of Random-Feature MPNNs Across Graph Sizes

The paper investigates how continuous random node features affect the expressivity of message‑passing neural networks (MPNNs). It introduces a population‑level framework for size‑uniform approximation, showing that continuous random features can be quantized to finitely many colors with negligible error, allowing transfer of finite‑color distinguishability limits to size‑uniform approximation. The authors prove that such MPNNs are not size‑uniformly universal, analyze expressivity gains from colors and independent trials, establish incomparability with higher‑order Weisfeiler‑Leman methods, and provide finite‑color MPNN constructions for tree subgraph isomorphism and a local minimum spanning tree task.

By Robert R. Nerem, Mitchell Black, Antonis Vasileiou, Christopher Morris, Yusu Wang