Florentin Guth

Florentin Guth

@florentinguth.bsky.social

Research fellow at @flatironinstitute.org and incoming Assistant Professor at MIT EECS. Science of deep learning.

200 followers118 following22 posts

I'm delighted to announce that I'll join MIT EECS as an Assistant Professor next Fall! I will be recruiting graduate students this cycle, please apply if you're interested in the science of deep learning! Despite the ambient doomerism, now is a great time to do research.

I'm late to the party, but I loved @randomwalker.bsky.social's annotated ICML keynote slides. He clearly puts into words so many vague thoughts I had (and didn't have). Highly recommended! It's a great preparation to answer my relatives’ actual questions about AI, unlike my own work 😅

Arvind Narayanan@randomwalker.bsky.social

I had the honor of giving a keynote at the International Conference on Machine Learning last week. I addressed the widespread anxiety about how we should adapt as AI capabilities increase. I was thrilled by the talk’s reception, so I have made my slides available www.cs.princeton.edu/~arvindn/tal...

Florentin Guth reposted

Applications are open for the Junior Theoretical Neuroscientists Workshop which will take place July 21-24, 2026 at the Center for Computational Neuroscience, @flatironinstitute.org Travel, lodging, and meals will be covered for accepted participants. Application deadline: April 15, 2026

I'll be in #NeurIPS2025 Dec 3-7, do reach out (atconf/email) if you want to chat (see below)! I'm on the faculty job market 👀 Come say hi to @zahra-kadkhodaie.bsky.social @eerosim.bsky.social and I at our poster on energy-based models Fri 11am #3700 (thread in quoted post) bsky.app/profile/flor...

Florentin Guth@florentinguth.bsky.social

What is the probability of an image? What do the highest and lowest probability images look like? Do natural images lie on a low-dimensional manifold? In a new preprint with Zahra Kadkhodaie and @eerosim.bsky.social, we develop a novel energy-based model in order to answer these questions: 🧵

Conversation topics: • science of deep learning: what experiments/theory do we need to figure what deep nets are doing? • anything at the intersection of high-dimensional probability and geometry • what we can do to replace these huge conferences (now more pressing than ever!)

Florentin Guth reposted

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Finally, we test the manifold hypothesis: what is the local dimensionality around an image? We find that this depends both on the image and the size of the local neighborhood, and there exists images with both large full-dimensional and small low-dimensional neighborhoods.

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These are the highest and lowest probability images in ImageNet64. An interpretation is that -log2 p(x) is the size in bits of the optimal compression of x: higher probability images are more compressible. Also, the probability ratio between these is 10^14,000! 🤯

High probability ≠ typicality: very high-probability images are rare. This is not a contradiction: frequency = probability density *multiplied by volume*, and volume is weird in high dimensions! Also, the log probabilities are Gumbel-distributed, and we don't know why!

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We call this approach "dual score matching". The time derivative constrains the learned energy to satisfy the diffusion equation, which enables recovery of accurate and *normalized* log probability values, even in high-dimensional multimodal distributions.

But how do we know our probability model is accurate on real data? In addition to computing cross-entropy/NLL, we show *strong* generalization: models trained on *disjoint* subsets of the data predict the *same* probabilities if the training set is large enough!

How do we train an energy model? Inspired by diffusion models, we learn the energy of both clean and noisy images along a diffusion. It is optimized via a sum of two score matching objectives, which constrain its derivatives with both the image (space) and the noise level (time).

We also propose a simple procedure to obtain good network architectures for the energy U: choose any pre-existing score network s and simply take the inner product with the input image y! We show that this preserves the inductive biases of the base score network: grad_y U ≈ s.

Florentin Guth reposted

A loose thought that's been bubbling around for me recently: when you think of a 'generic' big matrix, you might think of it as being close to low-rank (e.g. kernel matrices), or very far from low-rank (e.g. the typical scope of random matrix theory). Intuition ought to be quite different in each.

Some more random conversation topics: - what we should do to improve/replace these huge conferences - replica method and other statphys-inspired high-dim probability (finally trying to understand what the fuss is about) - textbooks that have been foundational/transformative for your work

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