Variational inference for SDEs driven by fractional noise
File(s)972_variational_inference_for_sdes.pdf (3.51 MB)
Accepted version
Author(s)
Daems, Rembert
Opper, Manfred
Crevecoeur, Guillaume
Birdal, Tolga
Type
Conference Paper
Abstract
We present a novel variational framework for performing inference in (neural) stochastic differential equations (SDEs) driven by Markov-approximate fractional Brownian motion (fBM). SDEs offer a versatile tool for modeling real-world continuous-time dynamic systems with inherent noise and randomness. Combining SDEs with the powerful inference capabilities of variational methods, enables the learning of representative function distributions through stochastic gradient descent. However, conventional SDEs typically assume the underlying noise to follow a Brownian motion (BM), which hinders their ability to capture long-term dependencies. In contrast, fractional Brownian motion (fBM) extends BM to encompass non-Markovian dynamics, but existing methods for inferring fBM parameters are either computationally demanding or statistically inefficient. In this paper, building upon the Markov approximation of fBM, we derive the evidence lower bound essential for efficient variational inference of posterior path measures, drawing from the well-established field of stochastic analysis. Additionally, we provide a closed-form expression to determine optimal approximation coefficients. Furthermore, we propose the use of neural networks to learn the drift, diffusion and control terms within our variational posterior, leading to the variational training of neural-SDEs. In this framework, we also optimize the Hurst index, governing the nature of our fractional noise. Beyond validation on synthetic data, we contribute a novel architecture for variational latent video prediction,-an approach that, to the best of our knowledge, enables the first variational neural-SDE application to video perception.
Date Issued
2024-05-07
Date Acceptance
2024-01-15
Citation
The Twelfth International Conference on Learning Representations, 2024
Journal / Book Title
The Twelfth International Conference on Learning Representations
Copyright Statement
© 2024 The Author(s).
Identifier
https://openreview.net/forum?id=rtx8B94JMS
Source
International Conference on Learning Representations (ICLR 2024)
Publication Status
Published
Start Date
2024-05-07
Finish Date
2024-05-11
Coverage Spatial
Vienna, Austria