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Dibya Ghosh

17 accepted papers

2025

$\pi_{0.5}$: a Vision-Language-Action Model with Open-World Generalization

CoRL 2025oral

In order for robots to be useful, they must perform practically relevant tasks in the real world, outside of the lab. While vision-language-action (VLA) models have demonstrated impressive results for end-to-end robot control, it remains an open question how far such models can generalize in the wil…

Cited by 0SourceScholar
2025

What Do Learning Dynamics Reveal About Generalization in LLM Mathematical Reasoning?

ICML 2025poster

Modern large language models (LLMs) excel at fitting finetuning data, but often struggle on unseen examples. In order to teach models genuine reasoning abilities rather than superficial pattern matching, our work aims to better understand how the learning dynamics of LLM finetuning shapes downstream…

Cited by 0SourcePDFScholar
2024

Octo: An Open-Source Generalist Robot Policy

RSS 2024poster

Large policies pretrained on diverse robot datasets have the potential to transform robotic learning: instead of training new policies from scratch, such generalist robot policies may be finetuned with only a little in-domain data, yet generalize broadly. However, to be widely applicable across a ra…

Cited by 327SourcePDFScholar
2024

Robotic Offline RL from Internet Videos via Value-Function Learning

ICRA 2024poster

Pre-training on Internet data has proven to be a key ingredient for broad generalization in many modern ML systems. What would it take to enable such capabilities in robotic reinforcement learning (RL)? Offline RL methods, which learn from datasets of robot experience, offer one way to leverage prio…

Cited by 4SourceScholar
2023

Accelerating Exploration with Unlabeled Prior Data

NeurIPS 2023poster

Learning to solve tasks from a sparse reward signal is a major challenge for standard reinforcement learning (RL) algorithms. However, in the real world, agents rarely need to solve sparse reward tasks entirely from scratch. More often, we might possess prior experience to draw on that provides cons…

2023

HIQL: Offline Goal-Conditioned RL with Latent States as Actions

NeurIPS 2023spotlight

Unsupervised pre-training has recently become the bedrock for computer vision and natural language processing. In reinforcement learning (RL), goal-conditioned RL can potentially provide an analogous self-supervised approach for making use of large quantities of unlabeled (reward-free) data. However…

2023

Reinforcement Learning from Passive Data via Latent Intentions

ICML 2023oral

Passive observational data, such as human videos, is abundant and rich in information, yet remains largely untapped by current RL methods. Perhaps surprisingly, we show that passive data, despite not having reward or action labels, can still be used to learn features that accelerate downstream RL. O…

2022

Distributionally Adaptive Meta Reinforcement Learning

NeurIPS 2022accept

Meta-reinforcement learning algorithms provide a data-driven way to acquire policies that quickly adapt to many tasks with varying rewards or dynamics functions. However, learned meta-policies are often effective only on the exact task distribution on which they were trained and struggle in the pres…

Cited by 19SourcePDFScholar
2021

Implicit Under-Parameterization Inhibits Data-Efficient Deep Reinforcement Learning

ICLR 2021poster

We identify an implicit under-parameterization phenomenon in value-based deep RL methods that use bootstrapping: when value functions, approximated using deep neural networks, are trained with gradient descent using iterated regression onto target values generated by previous instances of the value…

Cited by 132SourcePDFScholar
2021

Learning to Reach Goals via Iterated Supervised Learning

ICLR 2021oral

Current reinforcement learning (RL) algorithms can be brittle and difficult to use, especially when learning goal-reaching behaviors from sparse rewards. Although supervised imitation learning provides a simple and stable alternative, it requires access to demonstrations from a human supervisor. In…

2021

Why Generalization in RL is Difficult: Epistemic POMDPs and Implicit Partial Observability

NeurIPS 2021poster

Generalization is a central challenge for the deployment of reinforcement learning (RL) systems in the real world. In this paper, we show that the sequential structure of the RL problem necessitates new approaches to generalization beyond the well-studied techniques used in supervised learning. Whil…

Cited by 147SourcePDFScholar
2018

Divide-and-Conquer Reinforcement Learning

ICLR 2018poster

Standard model-free deep reinforcement learning (RL) algorithms sample a new initial state for each trial, allowing them to optimize policies that can perform well even in highly stochastic environments. However, problems that exhibit considerable initial state variation typically produce high-varia…

2018

Variational Inverse Control with Events: A General Framework for Data-Driven Reward Definition

NeurIPS 2018poster

The design of a reward function often poses a major practical challenge to real-world applications of reinforcement learning. Approaches such as inverse reinforcement learning attempt to overcome this challenge, but require expert demonstrations, which can be difficult or expensive to obtain in prac…

Cited by 155SourcePDFScholar