Nikolay Malkin

This paper builds bridges between two families of probabilistic algorithms: (hierarchical) variational inference (VI), which is typically us… (see more)ed to model distributions over continuous spaces, and generative flow networks (GFlowNets), which have been used for distributions over discrete structures such as graphs. We demonstrate that, in certain cases, VI algorithms are equivalent to special cases of GFlowNets in the sense of equality of expected gradients of their learning objectives. We then point out the differences between the two families and show how these differences emerge experimentally. Notably, GFlowNets, which borrow ideas from reinforcement learning, are more amenable than VI to off-policy training without the cost of high gradient variance induced by importance sampling. We argue that this property of GFlowNets can provide advantages for capturing diversity in multimodal target distributions.

2023-02-01

ICLR.cc/2023/Conference (poster)

Conditional Flow Matching: Simulation-Free Dynamic Optimal Transport

Alexander Tong

Nikolay Malkin

Guillaume Huguet

Yanlei Zhang

Jarrid Rector-Brooks

Kilian FATRAS

Guy Wolf

2023-01-01

arXiv.org (preprint)

GFlowOut: Dropout with Generative Flow Networks

Dianbo Liu

Moksh J. Jain

Bonaventure F. P. Dossou

Qianli Shen

Salem Lahlou

Anirudh Goyal

Nikolay Malkin

Chris Emezue

Dinghuai Zhang

Nadhir Hassen

Xu Ji

Kenji Kawaguchi

2023-01-01

ICML (published)

GFlowOut: Dropout with Generative Flow Networks

Dianbo Liu

Moksh J. Jain

Bonaventure F. P. Dossou

Qianli Shen

Salem Lahlou

Anirudh Goyal

Nikolay Malkin

Chris Emezue

Dinghuai Zhang

Nadhir Hassen

Xu Ji

Kenji Kawaguchi

2023-01-01

ICML (published)

Learning GFlowNets from partial episodes for improved convergence and stability

Kanika Madan

Jarrid Rector-Brooks

Maksym Korablyov

Emmanuel Bengio

Moksh J. Jain

Andrei Cristian Nica

Tom Bosc

Nikolay Malkin

Generative flow networks (GFlowNets) are a family of algorithms for training a sequential sampler of discrete objects under an unnormalized … (see more)target density and have been successfully used for various probabilistic modeling tasks. Existing training objectives for GFlowNets are either local to states or transitions, or propagate a reward signal over an entire sampling trajectory. We argue that these alternatives represent opposite ends of a gradient bias-variance tradeoff and propose a way to exploit this tradeoff to mitigate its harmful effects. Inspired by the TD(

2023-01-01

ICML (published)

A theory of continuous generative flow networks

Salem Lahlou

Tristan Deleu

Pablo Lemos

Dinghuai Zhang

Alexandra Volokhova

Alex Hernandez-Garcia

Lena Nehale Ezzine

Nikolay Malkin

2023-01-01

ICML (published)

A theory of continuous generative flow networks

Salem Lahlou

Tristan Deleu

Pablo Lemos

Dinghuai Zhang

Alexandra Volokhova

Alex Hernandez-Garcia

Lena Nehale Ezzine

Nikolay Malkin

Generative flow networks (GFlowNets) are amortized variational inference algorithms that are trained to sample from unnormalized target dist… (see more)ributions over compositional objects. A key limitation of GFlowNets until this time has been that they are restricted to discrete spaces. We present a theory for generalized GFlowNets, which encompasses both existing discrete GFlowNets and ones with continuous or hybrid state spaces, and perform experiments with two goals in mind. First, we illustrate critical points of the theory and the importance of various assumptions. Second, we empirically demonstrate how observations about discrete GFlowNets transfer to the continuous case and show strong results compared to non-GFlowNet baselines on several previously studied tasks. This work greatly widens the perspectives for the application of GFlowNets in probabilistic inference and various modeling settings.

2023-01-01

ICML (published)