Luca Ambrogioni
@lucamb.bsky.social
1.9K followers 120 following 40 posts
Assistant professor in Machine Learning and Theoretical Neuroscience. Generative modeling and memory. Opinionated, often wrong.
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lucamb.bsky.social
I am happy to share here our paper: "Spontaneous symmetry breaking in generative diffusion models", published at Neurips 2023.

We found that the generative capabilities of diffusion models are the result of a phase transition!

Preprint: arxiv.org/abs/2305.19693

Code: github.com/gabrielraya/...
Reposted by Luca Ambrogioni
robertrosenbaum.bsky.social
The University of Notre Dame is hiring 5 tenure or tenure-track professors in Neuroscience, including Computational Neuroscience, across 4 departments.

Come join me at ND! Feel free to reach out with any questions.

And please share!

apply.interfolio.com/173031
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lucamb.bsky.social
I am very happy to finally share something I have been working on and off for the past year:

"The Information Dynamics of Generative Diffusion"

This paper connects entropy production, divergence of vector fields and spontaneous symmetry breaking

link: arxiv.org/abs/2508.19897
lucamb.bsky.social
Many when the number of steps in the puzzle is in the thousands and any error leads to a wrong solution
lucamb.bsky.social
Have you ever asked your child to solve a simple puzzle in 60.000 easy steps?
Reposted by Luca Ambrogioni
cianodonnell.bsky.social
Students using AI to write their reports is like me going to the gym and getting a robot to lift my weights
lucamb.bsky.social
Generative decisions in diffusion models can be detected locally as symmetry breaking in the energy and globally as peaks in the conditional entropy rate.

The both corresponds to a (local or global) suppression of the quadratic potential (Hessian trace).
Reposted by Luca Ambrogioni
ckerren.bsky.social
🧠✨How do we rebuild our memories? In our new study, we show that hippocampal ripples kickstart a coordinated expansion of cortical activity that helps reconstruct past experiences.

We recorded iEEG from patients during memory retrieval... and found something really cool 👇(thread)
lucamb.bsky.social
Why? You can just mute out politics and owner's antics and it becomes perfecly fine again
lucamb.bsky.social
In continuous generative diffusion, the conditional entropy rate is the constant term that separates the score matching and the denoising score matching loss

This can be directly interpreted as the information transfer (bit rate) from the state x_t and the final generation x_0.
lucamb.bsky.social
Decisions during generative diffusion are analogous to phase transitions in physics. They can be identified as peaks in the conditional entropy rate curve!
Reposted by Luca Ambrogioni
Reposted by Luca Ambrogioni
canaesseth.bsky.social
Very excited that our work (together with my PhD student @gbarto.bsky.social and our collaborator Dmitry Vetrov) was recognized with a Best Paper Award at #AABI2025!

#ML #SDE #Diffusion #GenAI 🤖🧠
timrudner.bsky.social
Congratulations to the #AABI2025 Workshop Track Outstanding Paper Award recipients!
lucamb.bsky.social
Indeed. We are currently doing a lot of work on guidance, so we will likely try to use entropic time there as well soon
lucamb.bsky.social
The largest we have tried so far is EDM2 XL on 512 ImageNet. It works very well there!

We did not try with guidance so far
lucamb.bsky.social
I am very happy to share our latest work on the information theory of generative diffusion:

"Entropic Time Schedulers for Generative Diffusion Models"

We find that the conditional entropy offers a natural data-dependent notion of time during generation

Link: arxiv.org/abs/2504.13612
Reposted by Luca Ambrogioni
lucamb.bsky.social
Flow Matching in a nutshell.
Reposted by Luca Ambrogioni
arnosolin.bsky.social
I will be at #NeurIPS2024 in Vancouver. I’m looking for post-docs, and if you want to talk about post-doc opportunities, get in touch. 🤗

Here’s my current team at Aalto University: users.aalto.fi/~asolin/group/
Reposted by Luca Ambrogioni
inference.vc
Can language models transcend the limitations of training data?

We train LMs on a formal grammar, then prompt them OUTSIDE of this grammar. We find that LMs often extrapolate logical rules and apply them OOD, too. Proof of a useful inductive bias.

Check it out at NeurIPS:

nips.cc/virtual/2024...
NeurIPS Poster Rule Extrapolation in Language Modeling: A Study of Compositional Generalization on OOD PromptsNeurIPS 2024
nips.cc
Reposted by Luca Ambrogioni
jchodera.bsky.social
Excited to speak at the ELLIS ML4Molecules Workshop 2024 in Berlin!

moleculediscovery.github.io/workshop2024/
Photograph of Johannes Margraph and Günter Klambauer introducing the ELLIS ML4Molecules Workshop 2024 in Berlin at the Fritz-Haber Institute in Dahlem.
lucamb.bsky.social
Can we please stop sharing posts that legitimate murder? Please.
Reposted by Luca Ambrogioni
petar-v.bsky.social
Our team at Google DeepMind is hiring Student Researchers for 2025!

🧑‍🔬 Interested in understanding reasoning capabilities of neural networks from first principles?
🧑‍🎓 Currently studying for a BS/MS/PhD?
🧑‍💻 Have solid engineering and research skills?

🌟 We want to hear from you! Details in thread.
Reposted by Luca Ambrogioni
baopham.bsky.social
Diffusion models create beautiful novel images, but they can also memorize samples from the training set. How does this blending of features allow creating novel patterns? Our new work in Sci4DL workshop #neurips2024 shows that diffusion models behave like Dense Associative Memory networks.
On the left figure, it showcases the behavior of Hopfield models. Given a query (the initial point of energy descent), a Hopfield model will retrieve the closest memory (local minimum) to that query such that it minimizes the energy function. A perfect Hopfield model is able to store patterns in distinct minima (or buckets). In contrast, the right figure illustrates a bad Associative Memory system, where stored patterns share a distinctive bucket. This enables the creation of spurious patterns, which appear like mixture of stored patterns. Spurious patterns will have lower energy than the memories due to this overlapping.
lucamb.bsky.social
The naivete of these takes is always amusing

They could be equally applied to human beings, and they would work as well