Soledad Villar (Johns Hopkins): Statistics and DSI Joint Colloquium

Please join us for a Statistics and DSI joint colloquium.

Thursday, March 5
2:00pm – 3:00pm
Data Science Institute, Room 105
5460 S University Ave, Chicago, IL 60615

Title: Machine learning and symmetries

Abstract: Symmetries play a significant role in machine learning. In scientific applications, they often arise as constraints imposed by physical laws. More broadly, symmetries emerge whenever objects admit multiple ways to express them (for example, in graph machine learning). In addition, modern machine learning models are heavily overparameterized, so many distinct sets of parameters can represent the same function, revealing further underlying symmetries.

In this talk, we describe methods for incorporating symmetries into machine learning models using classical tools from algebra, including invariant theory and Galois theory. A particularly interesting feature of symmetry-preserving models is that they can be defined independently of the size or dimension of the input. The formalization of this setting, known as any-dimensional machine learning, is inspired by ideas from representation stability. In this talk we present a theoretical framework for understanding the assumptions imposed by such models, which allows us to align learning models with data of varying sizes and learning tasks in a principled way.

Any-dimensional models use a fixed set of parameters and can be evaluated on data of varying sizes. Hyperparameter transfer considers the complementary setting, in which the data are fixed while the model size varies, and studies how optimal hyperparameters (such as the learning rate) can be transferred from smaller models to larger ones. If time permits, we will also discuss recent connections between any-dimensional machine learning and hyperparameter transfer.

Bio: Soledad Villar is an assistant professor in the Department of Applied Mathematics and Statistics and at the Mathematical Institute for Data Science at Johns Hopkins University. Soledad is also a member of the Data Science and AI Institute.

She received her PhD in mathematics from University in Texas at Austin and was a research fellow at New York University as well as the Simons Institute in University of California Berkeley. Her mathematical interests are in computational methods for extracting information from data. In particular, she studies optimization for data science, machine learning, equivariant representation learning and graph neural networks.