##### Department of Mathematics,

University of California San Diego

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### Math 278B - Mathematics of information, data, and signals

## Ariel Jaffe

#### Yale University

## Recovering tree models via spectral graph theory

##### Abstract:

Modeling high dimensional data by latent tree graphical models is a common approach in multiple machine learning applications. In these models, the key task is to infer the structure of the tree, given only observations on its leaves. A canonical example of this setting is the tree of life, where the evolutionary history of a set of organisms is inferred by their nucleotide or protein sequences. \\ \\ In this talk, we will show that the tree structure is strongly related to the spectral properties of a fully connected graph, defined over the terminal nodes of the tree. This relation forms the theoretical basis of two new methods to recover latent tree models. Comparing our approach to several competing methods, we show that in many settings, spectral methods have stronger theoretical guarantees and work better in practice.

Host: Alex Cloninger

### November 10, 2020

### 10:30 AM

### https://ucsd.zoom.us/j/99096045418

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