Introducing the Differentiable Universe Initiative
What's the idea
- Vast amounts of data produced by upcoming surveys
- Controlling systematics is paramount
- All observe the same Universe under various modalities
How do we make the most of the available data ?
What if we could jointly forward simulate these surveys, and use the simulator for inference?
One example:
Weak Lensing
This is a Hierarchical Bayesian Model
aka
a stochastic simulator with some unknown tuning parameters
Advantages and Difficulties
- Provides a full model for the observations, beyond 2 or 3pt statistics, multiprobe
- Many systematics can now be explicitly modeled as part of the simulation
- We need to perform inference in a very large number of dimensions
=> We need more information out of the simulator to make the inference tractable
Let's build a full end-to-end differentiable model of the Universe
Why now?
- We are at the dawn of Stage IV surveys, it's a good time to work on novel methodologies
- Significant technological advances, with autodiff framework (like TensorFlow) and hardware acceleration
- Significant methodological advances in machine learning, and inference methodologies which make these problems tractable
- This is not a new idea, BCCP members have worked on differentiable simulations and optimization-based inference for years
Why an Initiative?
- This is a large interdisciplinary task, requires coordination and can use all the person-power it can get.
- Goals of the Initiative:
- Develop open source and high-quality software tools
- Foster an open, collaborative, and welcoming environment where people will want to contribute to the effort
- Help coordinate our interdisciplinary efforts towards making tools that can actually be used to analyse surveys.
- Develop open source and high-quality software tools
Where we are right now
- We have opened a GitHub repository to host discussions regarding the project:
https://github.com/DifferentiableUniverseInitiative/Initiative
- We have opened a Gitter Community for discussing the Initiative:
https://gitter.im/DifferentiableUniverseInitiative/community
- Our next steps are:
- Deciding on a structure and governance of the Initiative
- We want to be able to attract people, we also want everything to be the open, and discussed collaboratively
- We want to be able to attract people, we also want everything to be the open, and discussed collaboratively
- Starting building a Roadmap detailing the necessary building blocks
- Deciding on a structure and governance of the Initiative
Introducing the Differentiable Universe Initiative
By eiffl
