WORLD-MODELSCURRENT2026-08-27

Riemann-1.0: An Embodied World Action Model for Physical AI

Haofeng Sun, Jiangbo Pei, Fei Kang, Zexiang Liu, Yaokun Li, Boyi Jiang, Hua Xue, Cindy Zhou, Wei Li, Yichen Wei, Mengyin An, Fanliang Zhao, Biao Jiang, Zile Wang, Yang Liu, Yangguang Li

Riemann-1.0 unifies Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. Core ConceptsPolicyThe rule or model that maps observations or states to actions. Core ConceptsExecutionActually carrying out planned or predicted actions on the robot. and world Simulation & Sim-to-RealSimulationA virtual environment where robots can be trained or tested. in a single causal autoregressive model trained on 200K+ hours of diverse embodied data, achieving 85% success on long-horizon real-world Manipulation & TasksManipulationUsing a robot arm or hand to move or interact with objects. tasks—this means developers can now leverage pre-trained embodied world models that work across different Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. morphologies without task-specific Modern Robot LearningFine-tuningTaking a pretrained model and adapting it to a specific robot or task..

THE PROBLEM

This paper focuses on world models. Riemann-1.0 unifies Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. Core ConceptsPolicyThe rule or model that maps observations or states to actions. Core ConceptsExecutionActually carrying out planned or predicted actions on the robot. and world Simulation & Sim-to-RealSimulationA virtual environment where robots can be trained or tested. in a single causal autoregressive model trained on 200K+ hours of diverse embodied data, achieving 85% success on long-horizon real-world Manipulation & TasksManipulationUsing a robot arm or hand to move or interact with objects. tasks—this means developers can now leverage pre-trained embodied world models that work across different Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. morphologies without task-specific Modern Robot LearningFine-tuningTaking a pretrained model and adapting it to a specific robot or task.. Read the paper by tracking the Core ConceptsTaskThe job the robot is supposed to complete, such as pick-and-place, navigation, or drawer opening. definition, the Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. or data assumptions, and the evidence that supports the claimed improvement.

HOW IT WORKS

1

Task framing

The paper frames the work as world models. Start here because it defines what success means and which assumptions the rest of the method inherits.

2

Core method

Riemann-1.0 unifies Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. Core ConceptsPolicyThe rule or model that maps observations or states to actions. Core ConceptsExecutionActually carrying out planned or predicted actions on the robot. and world Simulation & Sim-to-RealSimulationA virtual environment where robots can be trained or tested. in a single causal autoregressive model trained on 200K+ hours of diverse embodied data, achieving 85% success on long-horizon real-world Manipulation & TasksManipulationUsing a robot arm or hand to move or interact with objects. tasks—this means developers can now leverage pre-trained embodied world models that work across different Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. morphologies without task-specific Modern Robot LearningFine-tuningTaking a pretrained model and adapting it to a specific robot or task.. When reading the method section, identify the inputs, the learned or engineered representation, and the Core ConceptsActionA command the robot sends to its motors, controller, or low-level system. or prediction produced by the system.

3

Data and supervision

For robotics work, the data story is part of the method: check whether the system depends on Imitation & Reinforcement LearningTeleoperation (teleop)A human remotely controlling the robot, often to collect demonstrations., Simulation & Sim-to-RealSimulationA virtual environment where robots can be trained or tested., internet video, human labels, or Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. rollouts.

4

Evaluation evidence

The paper should be judged through its Simulation & Sim-to-RealEvaluationMeasuring how well a robot system performs. protocol: what data is used, what Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. or simulator is tested, and which Evaluation & ResearchBaselineA reference method used for comparison. comparisons support the claim. Look for the gap between the headline result and the Simulation & Sim-to-RealDeploymentPutting the trained system on a real robot. setting you would actually care about.

KEY RESULTS

Main contributionConceptual contribution

Riemann-1.0 unifies Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. Core ConceptsPolicyThe rule or model that maps observations or states to actions. Core ConceptsExecutionActually carrying out planned or predicted actions on the robot. and world Simulation & Sim-to-RealSimulationA virtual environment where robots can be trained or tested. in a single causal autoregressive model trained on 200K+ hours of diverse embodied data, achieving 85% success on long-horizon real-world Manipulation & TasksManipulationUsing a robot arm or hand to move or interact with objects. tasks—this means developers can now leverage pre-trained embodied world models that work across different Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. morphologies without task-specific Modern Robot LearningFine-tuningTaking a pretrained model and adapting it to a specific robot or task..

WHY DEVELOPERS SHOULD CARE

Riemann-1.0 unifies Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. Core ConceptsPolicyThe rule or model that maps observations or states to actions. Core ConceptsExecutionActually carrying out planned or predicted actions on the robot. and world Simulation & Sim-to-RealSimulationA virtual environment where robots can be trained or tested. in a single causal autoregressive model trained on 200K+ hours of diverse embodied data, achieving 85% success on long-horizon real-world Manipulation & TasksManipulationUsing a robot arm or hand to move or interact with objects. tasks—this means developers can now leverage pre-trained embodied world models that work across different Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. morphologies without task-specific Modern Robot LearningFine-tuningTaking a pretrained model and adapting it to a specific robot or task..

LIMITATIONS

The main limitation to check is whether the claimed behavior holds outside the paper's reported setup. That means testing across different Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. embodiments, scenes, objects, and data distributions.

WHAT COMES NEXT

The practical next step is independent reproduction with clear baselines, ablations, and stress tests. For a developer, the useful follow-up is to map the paper's world models assumptions onto a concrete Core ConceptsRobotA physical system with sensors and actuators that can observe the world and take actions. stack, then test the smallest version of the method that could run end to end.

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