Gaussian Process Behaviour in Wide Deep Neural Networks

1 min readintermediate
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Overview

This article explores the theoretical properties of deep neural networks, specifically their relationship with Gaussian processes. It demonstrates that as the architecture of these networks becomes wider, the random functions they represent converge in distribution to a Gaussian process, extending prior research in the field.

What You'll Learn

1

How to understand the convergence of wide neural networks to Gaussian processes

2

Why Gaussian processes are significant in the context of deep learning

3

When to apply maximum mean discrepancy for evaluating convergence rates

Key Questions Answered

How do wide deep neural networks relate to Gaussian processes?
Wide deep neural networks, under broad conditions, converge in distribution to a Gaussian process as their architecture becomes increasingly wide. This relationship formalizes and extends previous findings by Neal (1996), providing a theoretical foundation for understanding the behavior of these networks.
What empirical methods are used to evaluate convergence rates?
The article employs maximum mean discrepancy as an empirical method to evaluate the convergence rates of random functions represented by wide neural networks to Gaussian processes. This approach allows for a quantitative assessment of how closely these networks align with Gaussian process behavior.
What are the predictive quantities of interest in Bayesian deep networks?
The article compares finite Bayesian deep networks to Gaussian processes in terms of key predictive quantities, finding that in some cases, the agreement between the two can be very close. This highlights the practical implications of Gaussian process behavior in deep learning applications.
What alternatives to Gaussian processes are discussed?
The article reviews non-Gaussian alternative models from the literature, discussing their desirability and potential applications. This provides insights into the broader landscape of probabilistic modeling in deep learning beyond Gaussian processes.

Key Actionable Insights

1
Understanding the convergence of wide neural networks to Gaussian processes can enhance model interpretability.
By recognizing this convergence, engineers can better predict model behavior and improve decision-making in model selection and tuning.
2
Using maximum mean discrepancy can provide a robust method for evaluating model convergence.
This technique allows practitioners to quantitatively assess how well their neural networks are approximating Gaussian processes, which can inform adjustments to network architecture.
3
Exploring non-Gaussian models can lead to innovative approaches in deep learning.
By considering alternatives to Gaussian processes, engineers can leverage diverse modeling techniques that may better fit specific data characteristics or application requirements.