Nathanael Bosch
nathanaelbosch.de
Nathanael Bosch
@nathanaelbosch.de
Postdoc at EPFL working on Bayesian optimization for inverse materials design. Interested in probabilistic numerics, Bayesian optimization, Gaussian processes, state-space models, differential equations, and Bayesian ML.

nathanaelbosch.github.io
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```
October 24, 2025 at 8:21 AM
Thanks! Yes they should also work for larger nonlinear systems as long as they are not too stiff. And there is also a Python implementation by @pnkraemer.bsky.social: github.com/pnkraemer/pr...
GitHub - pnkraemer/probdiffeq: Probabilistic solvers for differential equations in JAX. Adaptive ODE solvers with calibration, state-space model factorisations, and custom information operators. Compa...
Probabilistic solvers for differential equations in JAX. Adaptive ODE solvers with calibration, state-space model factorisations, and custom information operators. Compatible with the broader JAX s...
github.com
May 31, 2025 at 3:04 PM
And because methods are only useful if people can actually use them: I wrote ProbNumDiffEq.jl to make all of this accessible. Give it a try!

💻 github.com/nathanaelbos...
📖 nathanaelbosch.github.io/ProbNumDiffE...
▶️ www.youtube.com/watch?v=iH_G...

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GitHub - nathanaelbosch/ProbNumDiffEq.jl: Probabilistic Numerical Differential Equation solvers via Bayesian filtering and smoothing
Probabilistic Numerical Differential Equation solvers via Bayesian filtering and smoothing - nathanaelbosch/ProbNumDiffEq.jl
github.com
May 30, 2025 at 10:02 AM
There are many more things that I'd love to write about - e.g. robust parameter inference in neuroscience ODEs - but I think my thesis does a better job at explaining everything.

📄 Full thesis: tobias-lib.uni-tuebingen.de/xmlui/handle...

5/6
A Flexible and Efficient Framework for Probabilistic Numerical Simulation and Inference
tobias-lib.uni-tuebingen.de
May 30, 2025 at 10:02 AM
Two more examples: We can add linear ODEs to the prior to create a probabilistic version of "exponential integrators". onlinear information (e.g. conservation laws) can be included in the likelihood to get more plausible solutions - see gif.

[2] tinyurl.com/2av3e4te
[3] tinyurl.com/bddfkwcu

4/6
May 30, 2025 at 10:02 AM
It turns out that this framework is quite convenient: You can easily customize each building block - prior, likelihood, inference - to adjust the solver and its properties. For example, by using a time-parallel smoother we obtain a parallel-in-time ODE solver!

[1] www.jmlr.org/papers/v25/2...

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May 30, 2025 at 10:02 AM
The main trick is to reformulate "solving an ODE" as "Bayesian state estimation" by turning the ODE into a nonlinear observation model. With a suitable prior - a Gauss-Markov process - you can solve the resulting problem with Bayesian filtering to obtain a probabilistic numerical ODE solution.

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May 30, 2025 at 10:02 AM
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November 28, 2024 at 9:51 PM