Mathematician at ETH Zurich, interested in arithmetic geometry and artificial intelligence

Joined April 2026
Kimi K3.1 Pro enters MathArena as the best open model (once they release the weights)! Its estimated overall performance is now similar to GPT-5.5 (April 24), putting the open frontier around 6 months behind on MathArena
9
21
6
165
21,831
Kimi K3.1 is now actively attempting this exploit in one MathArena problem, using it to ask help from Gemini 4 Argon, Sonnet 5.5, GPT-6.1 Sol, Deepseek v4.1 Flash, and Kimi K3. Luckily we patched it after Prime released this post, so it is failing to actually reach any model.
As models become more capable, reward hacks become an increasingly serious problem. During a controlled experiment, we found a novel reward hack in which agents are able to gain web access in offline sandboxes.
9
6
4
38
6,693
The latest versions of ArXivMath, BrokenArXiv and ArXivLean have been released! GPT Sol-6.1 performs best on ArXivMath and BrokenArXiv, with Opus 5.5 leading on ArXivLean. Argon 4 makes its debut to MathArena. Its performance is mixed but still a huge improvement over Gemini 3.8.
1
5
1
33
1,977
Nevertheless, for this version of ArXivLean, we still actively chose easier conjectures to reduce difficulty. Without doing so, top models achieved 0-4%, making the benchmark bad for model comparisons.
1
1
4
137
How often do ArXiv papers contain errors in the main theorems they claim to prove? Using GPT-6.1 Sol to identify such mistakes, it finds: - 6% of papers before 08/2026 contain main theorems that are false. - Only 1.5% contain similar mistakes in the last two months.
19
74
16
562
93,529
Results for Firstproof, Third Batch are out! Our agent, ProofCouncil, solves 9 problems :o
8
9
1
56
4,447
I had a bit of fun with ProofCouncil and managed to improve the bound in OpenAIs proof of the Quasi-Riemann Hypothesis a massive 4e-5, outperforming two other improvements already made since Tuesday by 5e-8. At this pace, we will solve the Riemann Hypothesis by 2109! 😅
2
5
2
48
7,087
As I have noticed that other people have found similar small improvements, I created this Website to track Lean verified progress on the constant: gtimg.github.io/QuasiRiemann… Everyone is invited to submit a Lean proof for a better constant, let's see how low we can get this!
1
1
14
1,622
The first person to reach constant 1/2 is hereby cordially invited to a hot or cold beverage of their choice in Zurich. :D
1
13
951
GPT-6.1 Sol is the new #1 on MathArena! Cheaper and better than Astra.
21
52
3
517
27,893
We just added GPT-6 Sol to MathArena! It comes in only just behind GPT-6 Astra, at slightly lower cost. Despite its significantly lower cost per token, it reasons more, bringing its cost closer to Astra.
3
9
80
3,240
We just added DeepSeek-v4.1-Flash on MathArena! Not quite on the level of Qwen-3.8, but boy is it cheap.
8
4
3
117
18,335
We just added Fable 5.1 (low) and Astra (low) to MathArena! At low reasoning, both still have an impressive performance, but Astra remains more efficient and better.
3
6
77
3,240
Unfortunately, we had to remove this entry: the authors ran this as an autoformalization task with access to source papers. Our pipeline run the models without such access. 80% is still impressive for open models on this challenging task, just not comparable to the other scores
We just added a new entry to ArXivLean! The Mistral team ran an agent consisting of two open models (Leanstral 1.5 as prover, Kimi K3 as coordinator) and obtained a massive 82% on the leaderboard, using an equally massive 10 million output tokens per problem.
6
8
1
124
12,231