﻿ Manifold fitting: an invitation to statistics-清华大学求真书院

### Manifold fitting: an invitation to statistics

Abstract

While classical statistics has dealt with observations which are real numbers or elements of a real vector space, nowadays many statistical problems of high interest in the sciences deal with the analysis of data which consist of more complex objects, taking values in spaces which are naturally not (Euclidean) vector spaces but which still feature some geometric structure. The manifold fitting problem can go back to H. Whitney’s work in the early 1930s (Whitney (1992)), and finally has been answered in recent years by C. Fefferman’s works (Fefferman, 2006, 2005). The solution to the Whitney extension problem leads to new insights for data interpolation and inspires the formulation of the Geometric Whitney Problems (Fefferman et al. (2020, 2021a)): Assume that we are given a set \$Y \subset \mathbb{R}^D\$. When can we construct a smooth \$d\$-dimensional submanifold \$\widehat{M} \subset \mathbb{R}^D\$ to approximate \$Y\$, and how well can \$\widehat{M}\$ estimate \$Y\$ in terms of distance and smoothness? To address these problems, various mathematical approaches have been proposed (see Fefferman et al. (2016, 2018, 2021b)). However, many of these methods rely on restrictive assumptions, making extending them to efficient and workable algorithms challenging. As the manifold hypothesis (non-Euclidean structure exploration) continues to be a foundational element in statistics, the manifold fitting problem, merits further exploration and discussion within the modern statistical community. The talk will be partially based on some recent works of Yao with his co-authors along with some on-going progress.

Relevant references:

https://arxiv.org/abs/1909.10228

https://arxiv.org/abs/2304.07680

Speaker

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Yao Zhigang National University of SingaporeZhigang Yao is an Associate Professor in the Department of Statistics and Data Science at the National University of Singapore (NUS). He also holds a courtesy joint appointment with the Department of Mathematics at NUS. He is a Faculty Affiliate of the Institute of Data Science (IDS) at NUS. He received his Ph.D. in Statistics from University of Pitts...

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