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Sebastian Pokutta

@spokutta.bsky.social
51 followers 12 following 27 posts

Artificial Intelligence, Optimization, and Machine Learning. Prof @TUBerlin, Vice President @ZuseInstitute Home: www.pokutta.com Lab: iol.zib.de

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Sebastian Pokutta @spokutta.bsky.social · 16/08/2026
Paper: doi.org/10.1007/s12... Code: github.com/ZIB-IOL/Bos...
github.com
GitHub - ZIB-IOL/Boscia.jl: Mixed-Integer Convex Programming: Branch-and-bound with Frank-Wolfe-based convex relaxations
Mixed-Integer Convex Programming: Branch-and-bound with Frank-Wolfe-based convex relaxations - ZIB-IOL/Boscia.jl
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Sebastian Pokutta @spokutta.bsky.social · 16/08/2026
Our paper "Convex mixed-integer optimization with Frank-Wolfe methods" (Hendrych, Troppens, Besançon) won the MPC Outstanding Paper of the Year Award 2025 🎉 Result: Boscia.jl — compact open-source MINLP solver, FW over the convex hull of mixed-integer points in branch-and-bound. No outer approx.
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Sebastian Pokutta @spokutta.bsky.social · 14/07/2026
Yes fully agreed! Good point!!
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Sebastian Pokutta @spokutta.bsky.social · 13/07/2026
ICML 2026 was a blast. If you missed our spotlight on Neural Concept Verifiers, the blog post covers it in ~5 minutes. Paper: arxiv.org/abs/2507.07532 Blog: www.pokutta.com/blog/neural... Joint with Turan, Asadulla, Steinmann, Kersting, Stammer. #ICML2026 #NeuralConceptVerifier #XAI
pokutta.com
Neural Concept Verifiers: Proving with Concepts, not Pixels
TL;DR: This is a short summary of our paper Neural Concept Verifier: Scaling Prover-Verifier Games via Concept Encodings by Berkant Turan, Suhrab Asadulla, David Steinmann, Kristian Kersting, Wolfgang Stammer, and Sebastian Pokutta. The paper was accepted as a spotlight at ICML 2026 (top ~2.2% of submissions). In a nutshell, we move Prover-Verifier Games from pixel space to concept space: a prover selects a sparse set of human-readable concepts, a verifier must classify using only those concepts, and an adversarial prover tests whether the verifier can be fooled. The result is a scalable route to verifiable, nonlinear concept-based classification on datasets…
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Sebastian Pokutta @spokutta.bsky.social · 04/07/2026
The preprint is online now: arxiv.org/abs/2606.31640. Joint work with Volker Kaibel. Worth noting: the agent ran on locally-deployed DeepSeek V4 flash + GLM 5.2, not expensive closed-weight LLMs.
arxiv.org
A Counterexample to Ziegler's Cross-Polytope Conjecture for...
Ziegler proved that every simplicial $d$-dimensional $0/1$-polytope has at most $2d$ vertices, and asked whether equality forces the polytope to be centrally symmetric and hence, equivalently, a...
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Sebastian Pokutta @spokutta.bsky.social · 04/07/2026
The agent created a flawed proof, then attempted Lean 4 formalization. The formalization failed. From the failure it extracted a combinatorial condition that led to an actual counterexample: 14 vertices in {0,1}⁷ whose convex hull is simplicial but not centrally symmetric.
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Sebastian Pokutta @spokutta.bsky.social · 04/07/2026
Last week in Magdeburg, Germany I demoed our agentic research framework (arxiv.org/abs/2603.15914) when visiting Volker Kaibel & Sebastian Sager. Volker suggested testing Ziegler's cross-polytope conjecture for simplicial 0/1-polytopes.
arxiv.org
The Agentic Researcher: A Practical Guide to AI-Assisted Research...
AI tools and agents are reshaping how researchers work, from proving theorems to training neural networks. Yet for many, it remains unclear how these tools fit into everyday research practice....
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Sebastian Pokutta @spokutta.bsky.social · 01/06/2026
We prove this works on real research: from mathematical proofs (Frank-Wolfe lower bounds) to mixed-integer solvers (Boscia.jl). See you in Seoul! 📖 arxiv.org/abs/2603.15914 💻 github.com/ZIB-IOL/The... 📝 www.pokutta.com/blog/agenti...
pokutta.com
The Agentic Researcher
TL;DR: This is a summary of our recent paper The Agentic Researcher: A Practical Guide to AI-Assisted Research in Mathematics and Machine Learning by Max Zimmer, Nico Pelleriti, Christophe Roux, and Sebastian Pokutta augmented with some personal perspectives and thoughts. The main point is not that AI can now “do research” in some vague science-fiction sense. The more useful point is that, with the right workflow, general CLI coding agents can already act like research associates: they can write proofs, formulate conjectures, implement ideas, run experiments, document failures, verify intermediate claims, and keep going for hours, while the researcher remains responsible for idea generation, creativity, direction, judgment, and final verification.
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Sebastian Pokutta @spokutta.bsky.social · 01/06/2026
The key is the model-harness interaction. Our framework implements "The 10 Commandments of Agentic Research" to establish strict system-level guardrails: 🛠️ Verification-first: auto-testing claims before advancing 📄 Log everything: tracking errors & negative results
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Sebastian Pokutta @spokutta.bsky.social · 01/06/2026
Thrilled that "The Agentic Researcher" (joint w/ Max Zimmer, Nico Pelleriti, & Christophe Roux) is accepted as an Oral at the ICML 2026 AI4Research workshop in Seoul! 🇰🇷 Let's move AI in science beyond writing assistants to rigorous, autonomous collaborators. 🧵👇
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Sebastian Pokutta @spokutta.bsky.social · 31/05/2026
Great panel at @JWI_Berlin on 'The Cucumber's Dream' w/ Katrin Frisch, Tobias Wilke & Jennifer Haase. What happens to creativity when AI writes literature? We are still very much at the beginning of this journey, and where we'll end up is wide open. 🤖📚 #AI #literature
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Sebastian Pokutta @spokutta.bsky.social · 16/05/2026
Paper (Haase & Pokutta, 2026): doi.org/10.5281/zen... Blog post: www.pokutta.com/blog/hidden... The tokenizer is part of the model's interface to language and therefore part of the product, the economics, and the fairness story.
pokutta.com
The Hidden Cost of Tokenization
TL;DR: This is a short summary of our position paper The Hidden Cost of Tokenization: Why (most) Non-English Speakers Pay More for Less by Jennifer Haase and Sebastian Pokutta. The basic point is simple: tokenization is not a neutral preprocessing step. It determines how much users pay, how much context they get, how much compute is burned, and potentially how well a model can reason in a language. The same semantic content can require 1.3x, 5x, or even more than 10x as many tokens depending on the language-tokenizer pairing.
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Sebastian Pokutta @spokutta.bsky.social · 16/05/2026
What could change: • Model cards should report token multipliers by language, not just 'supports 100+ languages' • Tokenizer fertility and effective-context ratios should be standard diagnostics • Audit real token counts before launching multilingual products
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Sebastian Pokutta @spokutta.bsky.social · 16/05/2026
But it's not just economics. There is also cognitive friction: When a tokenizer cuts across meaningful linguistic units, the model reconstructs meaning through a worse interface. The basic units of prediction and attention are misaligned with the units that carry meaning.
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Sebastian Pokutta @spokutta.bsky.social · 16/05/2026
A 128k context window isn't 128k in every language. If Bengali needs ~6× the tokens of English, you get ~1/6 the usable semantic budget. Fewer examples fit. Less document context. Reasoning traces hit the limit sooner. Longer latency too. Support ≠ parity.
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Sebastian Pokutta @spokutta.bsky.social · 16/05/2026
Here's the invisible tax: Most LLM APIs charge per token. But the same semantic content can need 1.3×, 5×, or 10×+ as many tokens depending on the language-tokenizer pairing. Non-English speakers pay more for less: because the infrastructure encoded a preference.
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Sebastian Pokutta @spokutta.bsky.social · 16/05/2026
New paper (with Jennifer Haase): the hidden cost of tokenization. Tokenization is not a neutral preprocessing step. It determines how much you pay, how much context you get, how much compute burns, and how well a model reasons in your language. 🧵 thread:
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Sebastian Pokutta @spokutta.bsky.social · 05/05/2026
A few weeks ago I talked about using Pi with Qwen3.6 27B locally - which (still) is a beast. This Pi plugin squeezes out even more: score outcomes -> use reflective prompt evaluation -> inject small priors. Improves the model w/o retraining/fine-tuning. github.com/pokutta/pi-...
github.com
GitHub - pokutta/pi-prior-plugin: Context priors plugin for pi
Context priors plugin for pi . Contribute to pokutta/pi-prior-plugin development by creating an account on GitHub.
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Sebastian Pokutta @spokutta.bsky.social · 25/04/2026
Qwen 3.6 27B + Pi on a MacBook Pro, fully local: a beast. 27B dense model, flagship-level agentic coding, running entirely on hardware in your hands. Speed is impressive, Utility is extremely high. It punches orders of magnitude above its weight. Local AI is getting real.
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Sebastian Pokutta @spokutta.bsky.social · 23/04/2026
Very curious to see how this performs for AI/reasoning stuff in our agentic researcher harness. GPT 5.4 xhigh was already a significant upgrade and has become our go-to model at this point with autonomous loops running for 10+ hours straight producing formally verified output.
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Sebastian Pokutta @spokutta.bsky.social · 23/04/2026
Much of the current AI-for-mathematics discussion is framed as a contest between learned systems and classical methods, often missing the point. It is not AI vs classical, but where AI belongs in the stack. Three examples from our work: www.pokutta.com/blog/not-ev... #ai #math #agentic
pokutta.com
Not every discovery needs an LLM
TL;DR: AI-driven scientific discovery with systems such as AlphaTensor, AlphaEvolve, etc is en vogue and we are also heavily invested in that space. However, these LLM- and RL-driven approaches, while impressive often in themselves, are not always the right tool to get the job done. In this post I will talk about three recent projects from our group that take different angles on LLM- and RL-driven mathematical discovery systems. Two of them revisit classical problems made famous through these AI systems and show that classical structured search matches or beats them on these specific problem classes; with a tiny fraction of the compute. The third example goes the other way around: AI not as discovery engine, but an AI-accelerated subroutine sits inside a classical structured search and lets us settle a thirty-year-old conjecture on real algebraic plane curves of degree seven. This points to an interesting shift in the recent AI vs. classical discussion: it is not so much about whether
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Sebastian Pokutta @spokutta.bsky.social · 13/04/2026
Also do not forget to check out the nice work by Grimmer and Liu (arxiv.org/abs/2602.22608) that shortly appeared after ours; it nicely complements our story.
arxiv.org
Lower Bounds for Linear Minimization Oracle Methods Optimizing...
We consider the oracle complexity of constrained convex optimization given access to a Linear Minimization Oracle (LMO) for the constraint set and a gradient oracle for the $L$-smooth, strongly...
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Sebastian Pokutta @spokutta.bsky.social · 13/04/2026
The construction is unusual: instead of searching for bad initializations, we build them backward from the optimum. With J. Halbey, D. Deza, M. Zimmer, C. Roux, B. Stellato. 📄 arxiv.org/abs/2602.04378 📝 Blog with interactive widgets: www.pokutta.com/blog/fw-low...
pokutta.com
An uncommon approach to lower bounds for Frank-Wolfe on strongly convex sets
TL;DR: This is a short summary of our paper Lower Bounds for Frank-Wolfe on Strongly Convex Sets by Jannis Halbey, Daniel Deza, Max Zimmer, Christophe Roux, Bartolomeo Stellato, and Sebastian Pokutta. We prove a matching $\Omega(1/\sqrt{\varepsilon})$ lower bound for Frank-Wolfe on strongly convex sets, showing that Garber and Hazan’s 2015 upper bound is tight. The construction of the lower bound deviates from the standard route quite a bit: instead of searching for worst-case initializations, we build them backward from the optimum.
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Sebastian Pokutta @spokutta.bsky.social · 13/04/2026
For a decade it was open whether Frank-Wolfe's O(1/√ε) rate on strongly convex sets is tight. We show it is: Ω(1/√ε), even for a simple quadratic on a unit ball.
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Sebastian Pokutta @spokutta.bsky.social · 05/12/2025
SCIP Optimization Suite 10.0 is out 🎉 → Numerically exact solving mode for rational MILPs → 9-20% faster on hard MINLPs → IIS detection for debugging infeasible models → Better symmetry handling ... and many more For full details see: www.pokutta.com/blog/resear... #optimization
pokutta.com
SCIP Optimization Suite 10.0: Exact Solving, Better Decompositions, and a More Productive Ecosystem
TL;DR: SCIP Optimization Suite 10.0 brings a numerically exact solving mode for rational MILPs, noticeable performance gains for MILP/MINLP, stronger presolving and symmetry handling, better heuristics and conflict analysis, IIS detection, and major updates to GCG, PaPILO, PySCIPOpt, and MIP-DD.
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Sebastian Pokutta @spokutta.bsky.social · 01/10/2025
Our book on conditional gradients and Frank-Wolfe methods with Gábor Braun, @ACarderera, @CyrilleCmbt, Hamed Hassani, @aminkarbasi and Aryan Mokhtari just appeared in the MOS-SIAM Series on Optimization #ml #optimization #ai epubs.siam.org/doi/book/10...
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Sebastian Pokutta @spokutta.bsky.social · 30/09/2025
New blog post: committing to secrets via hashing - a short, first-principles introduction #crypto #hashing => www.pokutta.com/blog/hashed...
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