Probabilistic inference, Deep learning, Generative models, Representation Learning, Geometry

I am a second year DPhil student of statistics at the University of Oxford supervised by Prof. Yee Whye Teh and Ryota Tomioka from Microsoft Research. Previously, I received a joint MSc. from Ecole des Ponts ParisTech and Ecole Normale Supérieure Paris-Saclay. My research interests lie in the fields of probabilistic generative models, representation learning and geometry.

Publications

2019

E. Mathieu
,
T. Rainforth
,
N. Siddharth
,
Y. W. Teh
,
Disentangling Disentanglement in Variational Autoencoders, in Proceedings of the 36th International Conference on Machine Learning, Long Beach, California, USA, 2019, vol. 97, 4402–4412.

We develop a generalisation of disentanglement in VAEs—decomposition of the latent representation—characterising it as the fulfilment of two factors: a) the latent encodings of the data having an appropriate level of overlap, and b) the aggregate encoding of the data conforming to a desired structure, represented through the prior. Decomposition permits disentanglement, i.e. explicit independence between latents, as a special case, but also allows for a much richer class of properties to be imposed on the learnt representation, such as sparsity, clustering, independent subspaces, or even intricate hierarchical dependency relationships. We show that the β-VAE varies from the standard VAE predominantly in its control of latent overlap and that for the standard choice of an isotropic Gaussian prior, its objective is invariant to rotations of the latent representation. Viewed from the decomposition perspective, breaking this invariance with simple manipulations of the prior can yield better disentanglement with little or no detriment to reconstructions. We further demonstrate how other choices of prior can assist in producing different decompositions and introduce an alternative training objective that allows the control of both decomposition factors in a principled manner.

@inproceedings{pmlr-v97-mathieu19a,
title = {Disentangling Disentanglement in Variational Autoencoders},
author = {Mathieu, Emile and Rainforth, Tom and Siddharth, N and Teh, Yee Whye},
booktitle = {Proceedings of the 36th International Conference on Machine Learning},
pages = {4402--4412},
year = {2019},
editor = {Chaudhuri, Kamalika and Salakhutdinov, Ruslan},
volume = {97},
series = {Proceedings of Machine Learning Research},
address = {Long Beach, California, USA},
month = {09--15 Jun},
publisher = {PMLR}
}

@inproceedings{BloemReddy:etal:2018,
author = {Bloem-Reddy, Benjamin and Foster, Adam and Mathieu, Emile and Teh, Yee Whye},
booktitle = {Conference on Uncertainty in Artificial Intelligence},
title = {Sampling and Inference for Beta Neutral-to-the-Left Models of Sparse Networks},
month = aug,
year = {2018}
}

2017

B. Bloem-Reddy
,
E. Mathieu
,
A. Foster
,
T. Rainforth
,
H. Ge
,
M. Lomelí
,
Z. Ghahramani
,
Y. W. Teh
,
Sampling and inference for discrete random probability measures in probabilistic programs, NIPS Workshop on Advances in Approximate Bayesian Inference, 2017.

We consider the problem of sampling a sequence from a discrete random probability measure (RPM) with countable support, under (probabilistic) constraints of finite memory and computation. A canonical example is sampling from the Dirichlet Process, which can be accomplished using its stick-breaking representation and lazy initialization of its atoms. We show that efficiently lazy initialization is possible if and only if a size-biased representation of the discrete RPM is used. For models constructed from such discrete RPMs, we consider the implications for generic particle-based inference methods in probabilistic programming systems. To demonstrate, we implement SMC for Normalized Inverse Gaussian Process mixture models in Turing.

@article{bloemreddy2017rpm,
title = {Sampling and inference for discrete random probability measures in probabilistic programs},
author = {Bloem-Reddy, Benjamin and Mathieu, Emile and Foster, Adam and Rainforth, Tom and Ge, Hong and Lomelí, María and Ghahramani, Zoubin and Teh, Yee Whye},
journal = {NIPS Workshop on Advances in Approximate Bayesian Inference},
year = {2017}
}