Portrait de Pablo Lemos

Pablo Lemos

Postdoctorat - UdeM
Superviseur⋅e principal⋅e
Co-supervisor
Sujets de recherche
Biologie computationnelle
Modèles génératifs
Modèles probabilistes

Publications

On diffusion models for amortized inference: Benchmarking and improving stochastic control and sampling
On diffusion models for amortized inference: Benchmarking and improving stochastic control and sampling
We study the problem of training diffusion models to sample from a distribution with a given unnormalized density or energy function. We ben… (voir plus)chmark several diffusion-structured inference methods, including simulation-based variational approaches and off-policy methods (continuous generative flow networks). Our results shed light on the relative advantages of existing algorithms while bringing into question some claims from past work. We also propose a novel exploration strategy for off-policy methods, based on local search in the target space with the use of a replay buffer, and show that it improves the quality of samples on a variety of target distributions. Our code for the sampling methods and benchmarks studied is made public at https://github.com/GFNOrg/gfn-diffusion as a base for future work on diffusion models for amortized inference.
Sequence-Augmented SE(3)-Flow Matching For Conditional Protein Generation.
Improving Gradient-guided Nested Sampling for Posterior Inference
We present a performant, general-purpose gradient-guided nested sampling algorithm, …
Bayesian Imaging for Radio Interferometry with Score-Based Priors
No'e Dia
M. J. Yantovski-Barth
Micah Bowles
A. Scaife
U. Montŕeal
Ciela Institute
Flatiron Institute
Learning an Effective Evolution Equation for Particle-Mesh Simulations Across Cosmologies
The search for the lost attractor
Mario Pasquato
Syphax Haddad
Pierfrancesco Di Cintio
No'e Dia
Mircea Petrache
Ugo Niccolo Di Carlo
Alessandro A. Trani
Towards equilibrium molecular conformation generation with GFlowNets
Cheng-Hao Liu
Santiago Miret
Luca Thiede
Alan Aspuru-Guzik
Sampling diverse, thermodynamically feasible molecular conformations plays a crucial role in predicting properties of a molecule. In this pa… (voir plus)per we propose to use GFlowNet for sampling conformations of small molecules from the Boltzmann distribution, as determined by the molecule's energy. The proposed approach can be used in combination with energy estimation methods of different fidelity and discovers a diverse set of low-energy conformations for highly flexible drug-like molecules. We demonstrate that GFlowNet can reproduce molecular potential energy surfaces by sampling proportionally to the Boltzmann distribution.
Posterior Sampling of the Initial Conditions of the Universe from Non-linear Large Scale Structures using Score-Based Generative Models
Matthew Ho
Shirley Ho
Benjamin Wandelt
Sampling-Based Accuracy Testing of Posterior Estimators for General Inference
Sampling-Based Accuracy Testing of Posterior Estimators for General Inference
A theory of continuous generative flow networks
Generative flow networks (GFlowNets) are amortized variational inference algorithms that are trained to sample from unnormalized target dist… (voir plus)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.