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Main Authors: Mao, Cheng, Zhang, Shenduo
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2407.11932
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author Mao, Cheng
Zhang, Shenduo
author_facet Mao, Cheng
Zhang, Shenduo
contents In this largely expository note, we present an impossibility result for inner product recovery in a random geometric graph or latent space model using the rate-distortion theory. More precisely, suppose that we observe a graph $A$ on $n$ vertices with average edge density $p$ generated from Gaussian or spherical latent locations $z_1, \dots, z_n \in \mathbb{R}^d$ associated with the $n$ vertices. It is of interest to estimate the inner products $\langle z_i, z_j \rangle$ which represent the geometry of the latent points. We prove that it is impossible to recover the inner products if $d \gtrsim n h(p)$ where $h(p)$ is the binary entropy function. This matches the condition required for positive results on inner product recovery in the literature. The proof follows the well-established rate-distortion theory with the main technical ingredient being a lower bound on the rate-distortion function of the Wishart distribution which is interesting in its own right.
format Preprint
id arxiv_https___arxiv_org_abs_2407_11932
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Impossibility of latent inner product recovery via rate distortion
Mao, Cheng
Zhang, Shenduo
Statistics Theory
Information Theory
Social and Information Networks
Machine Learning
62B10
In this largely expository note, we present an impossibility result for inner product recovery in a random geometric graph or latent space model using the rate-distortion theory. More precisely, suppose that we observe a graph $A$ on $n$ vertices with average edge density $p$ generated from Gaussian or spherical latent locations $z_1, \dots, z_n \in \mathbb{R}^d$ associated with the $n$ vertices. It is of interest to estimate the inner products $\langle z_i, z_j \rangle$ which represent the geometry of the latent points. We prove that it is impossible to recover the inner products if $d \gtrsim n h(p)$ where $h(p)$ is the binary entropy function. This matches the condition required for positive results on inner product recovery in the literature. The proof follows the well-established rate-distortion theory with the main technical ingredient being a lower bound on the rate-distortion function of the Wishart distribution which is interesting in its own right.
title Impossibility of latent inner product recovery via rate distortion
topic Statistics Theory
Information Theory
Social and Information Networks
Machine Learning
62B10
url https://arxiv.org/abs/2407.11932