Disclaimers:
- I am one of the hosts of P&P, but this text represents my personal experience and opinions, which do not affect the way in which I contribute to running this platform. Moreover, this is completely independent of the views of the other hosts.
- I have personally reached out to all the people involved in this story, the only ones that did not write back with comments are the three of OpenAI, so they will remain nameless (just like in the 1 August announcement).
- Whatever mathematics you see below can be safely ignored. The human story is what I am most trying to convey.
Last year I co-organised a workshop on metric approximations of groups and their stability. This is a series of problems that until now were largely motivated as stepping stones for finding non-approximable groups, which was successful for the unnormalised Schatten p-norm, but only gave conditional results in the context of soficity, hyperlinearity and MF. In his talk, Alon Dogon called these the “big three” problems in the topic of metric approximations of groups. Andreas Thom’s 2018 ICM talk shares a similar message. Flash forward, and less than a year later:1
- 1 August: OpenAI finds a non-sofic group.
- 13-14 August: Sauers and Eckhardt, independently, find a non-MF group, through ChatGPT 5.6 Sol.
- 20 September: Liu finds a non-hyperlinear group, through the Danus system.
The “big three”, all fallen in less than two months, to various AI systems. This came about in a very messy way. We are entering a new regime where if you prove a big result with AI assistance, there are good chances that someone else, who is better at deploying agents than you, or has invested more money than you, could scoop you tomorrow. No one knows how to deal with these new dynamics, and messiness naturally ensues. I hope that telling the whole story from my point of view could be instructive, although I won’t offer any solutions. While I am not involved in any of the above results, I played a role in part of the story, and have contributed to the messiness to some extent (not on purpose!). This post is entirely human-generated, so I apologise in advance for the chatty structure and unimaginative vocabulary.
The first non-sofic groups
On Friday 31 July, Srivatsav Kunnawalkam Elayavalli shared with me on whatsapp a PDF, authored by OpenAI, and titled “Nonsofic groups exist”. I immediately dropped everything I was doing, sent it to Henry Bradford and Alon Dogon (who had already received it from another colleague), and we jumped on a call to go through it. We were in disbelief, but also full of excitement for seeing the solution to a problem at the centre of a major thread of research we were active in. Something that was apparent from this writeup was that no expert had been involved in it. As a standout example, the abstract, introduction, and end of the paper, insisted on the fact that, once the non-sofic group was constructed, a finitely presented one could be “explicitly” constructed as well. But then this step was done with a trick that is well-known to experts, and is far from explicit. I imagine that the model had been prompted with “find a finitely presented non-sofic group”, and this was its attempt at justifying having solved the actual prompted problem.
I learned that Michael Chapman had received the draft directly from people at OpenAI, and so I sent him various comments, including the one above.2 He wrote to three people at OpenAI, with me in cc, relaying my comments, which resulted in some back and forth. In parallel, I started an email thread with various experts, in particular people whose work was being used in the solution, proposing that we write a response document together, analogous to the one that appeared after the disproof of the unit distance conjecture. I also told this to the three of OpenAI, and they said that they would be happy to see a response document, but that they planned to announce the result on Monday 3 August. So it seemed like all of the weekend would be dedicated to writing this response document.
But on Saturday 1 August, the result was announced (with most of the comments implemented), together with 9 others. Apparently the paper had already circulated too much to wait two extra days.
The announcement of OpenAI
The original announcement included this sentence:
Today we are sharing a selection of ten results to problems that have been open and have seen no progress on the main result for at least a decade.
It is clear to anyone reading the solution that the proof is entirely dependent on a paper of Kun from 2016 and a paper of Kun and Thom from 2019. In fact, the key proposition in the OpenAI proof can be seen as a bridge between the conclusion of Kun and the hypothesis of Kun-Thom. The writeup appropriately attributed these results, but the announcement, which is what most people read and accepted as a fact, ignored this.
After the key proposition, the second step in the solution consists in finding a concrete non-example. This used a connection between the binary Leavitt algebra and Thompson’s group that was discovered independently by Birget and Nekrashevych in 2004 (neither of these papers was cited in the 1 August writeup). It also relied on work of Ershov and Jaikin-Zapirain to prove that elementary matrices over the binary Leavitt algebra have property (T). I thought that this was overkill and made the result look harder than it was, and that the key proposition was the only genuine novelty. So I quickly put together an alternative construction, hoping that it would clarify this point, and bring the attention away from the specifics of the construction, and onto the key proposition, and just how much it relied on work of Kun and Thom.
I was dreading the moment that people would pick up this story and repeat the “no progress for at least a decade” line without questioning it. So I wrote to several youtubers and scientific news outlets, offering to speak with them and set the story straight; many of my colleagues did the same. This resulted in a video on Alvaro Lozano-Robledo’s youtube channel, where I explained the problem, the solution, and criticised this dishonest framing. Remember this for later. In the following days, articles appeared on New Scientist, Scientific American and The Verge, which included comments from me about this framing, and I was also interviewed by 3Blue1Brown for an upcoming documentary about maths and AI.
In parallel, Andreas Thom wrote an email to the three of OpenAI, where I was cc’d, calling them out. They answered:
The wording in the announcement was intended to refer to other results in the collection.
I will leave it to the reader to decide whether “ten results to problems that have been open for at least a decade” could have been intended to refer to only some of these ten problems. The rest of the answer was problematic for other reasons that are detailed in this post of Andreas, and that I will not get into here.
The wording in the announcement has since been quietly changed. But I think it’s important to remember that complaining about it made a difference. A few days later Anthropic announced their “2/3 of zeros” result, and I was pleased to see that they did not make the same mistake. Sure, this was a deliberate PR move on their part to distance themselves from the practices of OpenAI, but hey, whatever works.
More non-sofic groups
A couple of weeks before the OpenAI announcement, Vadim Alekseev and Andreas Thom had started circulating a preprint, which has since appeared essentially unchanged, building upon the 2019 Kun-Thom paper, and strengthening it. The key technical step is a “centraliser rigidity” theorem: the centraliser of a sofic approximation of a property (T) group is “internal”. Combining this with some insights from the key proposition of OpenAI, Kun and Thom gave a new, more robust criterion for non-soficity, which subsumes the OpenAI one, and gives very nice new examples of non-sofic groups. In particular, this includes permutational wreath products of the form , where is “infranormal” (a new definition of Kun-Thom that comes naturally out of the assumptions in OpenAI’s key proposition), not normal, and both have property (T). For the same pair , another nice example of a non-sofic group is the double . This may be more mathematics than you wanted to hear but remember this for later.
They wrote this up in a preprint that appeared on the arXiv on 6 August 2026. It is worth mentioning that both of these human proofs relied on AI assistance for “drafting, editing, checking” and in the case of the more recent one, also “as an interactive proof assistant”. This is the least messy part of the story, and most likely the one that will eventually be “canonicalised“. Alekseev and Thom were already working on a detailed writeup of the whole proof, from Kun’s 2016 paper to the latest developments, but they might have to revise their plan now that a non-hyperlinear group has been found.
The first non-MF groups
On 13 August, I woke up to the following email from Scott Sauers:
I am a PhD student in computational biology (CS / stats / ML) and decided to set some AI agents loose on the question of whether all groups are hyperlinear, inspired by the OpenAI soficity result () I watched your discussion with Alvaro Lozano-Robledo, so I figured your perspective on the following would be valuable. Instead of proving the hyperlinearity result, GPT 5.6 Sol proved that a non-MF group exists, then formalized it in Lean. Do you have advice for how I should go about this as a non-specialist? I want to avoid, for example, mistakes like the improper credit attribution in the OpenAI announcement. I also want to avoid wasting anyone’s time () The paper likely contains some mistakes, does not yet have a 1:1 correspondence with the Lean code, and is written poorly. I don’t understand the proof, and have only recently begun to learn a bit of group theory.
It made sense that once a non-sofic group was discovered, many other related problems would follow, but I did not expect it to take less than two weeks, and to come from someone who has “only recently begun to learn a bit of group theory”. The initial writeup was long and hard to parse. Scott said he would work on making it more readable, and in the meantime I started an email thread with some experts:
I am sure you have seen that OpenAI found a non-sofic group on 1 August () The whole thing was a bit of a mess () So to avoid another thing like this, I would ask you that this conversation remains private until there is a consensus on the correctness, and a document to show for it. This is just a first email to let you know () I thought you’d appreciate the heads up, as with the non-sofic group it all happened in 24 hours, which for me was very stressful.
One of these experts was Caleb Eckhardt, who on 14 August replied with:
After Francesco’s message yesterday about Scott’s example I had ChatGPT come up with an example (they are groups considered by Kun and Thom). I wonder how similar it is to Scott’s example.
As it turns out both constructions were very similar. The one discovered by Scott was not directly defined as a wreath product, but relied on an embedding into (a central extension of a) wreath product à la Kun-Thom to prove that certain elements are non-trivial. The one discovered by Caleb was a wreath product à la Kun-Thom on the nose. The two writeups were also interesting to compare. Caleb expertly guided the model to find a non-example in the most efficient way, and rewrote it to put the emphasis on the main ideas, and only prove the existence of a non-MF group. A revised version has since been posted on the arXiv. Scott’s writeup was more exploratory in nature: it was much longer, included several detours that were not necessary to get to the main result, and several pages of “additional topics” that might be worth exploring, which is only natural when the person doing the prompting is learning about the field at the same time as they are proving a breakthrough result. The current writeup is available here, but Scott is still working on it, trying to make it match with the formalisation, and understand every step of it:
It feels odd to publish a preprint without actually understanding the proofs, even if I am confident they are correct.
Certain mathematicians (one comes to mind, that has been bragging about having written 48 papers in the last month) have a lot to learn from Scott.
Mathematically, as I mentioned, the examples are essentially the Kun-Thom wreath products. However much less is needed to produce a non-MF group, and this is reflected in Caleb’s writeup. So, while the discovery a non-MF group was motivated by the discovery of a non-sofic group, in retrospect it was much easier. The technical steps are also all very standard, and there is no seemingly unnatural construction at play. As Andreas noted:
This non-MF proof could have been found in 1995 or even earlier.
You’ll have noticed that in this section I have not been talking of “Caleb’s result”, but rather of “the result discovered by Caleb”. But this is just a placeholder, I do not really know what the right word is in this context. Again, Andreas put it best:
We should find a way as a community to deal with these kind of results and it seems hard to publish them in the old way and also wrong to attribute them entirely to AI. I propose to attribute them to the math community as a whole with due credit to the system that found the proof and the person that overlooked the editing. Second, the integration into the existing body of knowledge will remain as a task and a Lean certificate is not doing this at all. After all math, I think, is not about results but about human understanding of it.
The first non-hyperlinear groups
Remember the Alekseev-Thom paper, the one with the centraliser rigidity theorem? In that paper, they ask whether a similar result holds in the hyperlinear setting: the commutant of a hyperlinear approximation of a property (T) group is “internal”. On 10 August, Andreas Thom circulated a preprint (also using ChatGPT for drafting, editing, and as a proof assistant), showing that if this centraliser problem could be solved, then a non-hyperlinear group exists. In fact, the example is one of those from the Kun-Thom paper: a double , where is infranormal but not normal, and both have property (T). On 17 August he submitted this to the arXiv. It is available on his homepage since 25 August.
A small aside: what’s going on at the arXiv? I am sure you have heard from people that their submissions have been put on hold for a long time. I heard this from the 48-papers-in-a-month guy. I also heard it from Tarik Aougab, for the extended version of his post on this blog. And finally I heard it from Andreas. On the other hand, I have a colleague that recently wrote a paper that does not use AI in any way, and that one appeared on time. There seems to be some criterion related to AI by which arXiv is putting papers on hold, but what exactly the criterion is I don’t know: here it ranges from someone mass-producing AI papers (not all of them with AI disclosures), to someone writing about AI, to someone writing a normal amount of papers with some AI assistance that is duly disclosed.
Andreas’s paper appeared on the arXiv only on 24 September.3 And then on 20 September, Jihao Liu announced:4
Today, a Danus system consisting of seven workers, running for a total of 7 hours and 11 minutes, produced an example of a non-hyperlinear group.
Jihao Liu has been producing a lot of AI-generated results recently, thanks to a harness devised by him and colleagues: the Danus system. This is not dissimilar to the one that Scott Sauers has been using, but at a smaller scale. The writeup is available here. The announcement continues:
This paper has so far undergone only machine verification and has not yet been checked by a human. I had originally hoped to post it to arXiv only after completing a human verification. However, we discovered that there is a public AI project on GitHub continuously searching for non-hyperlinear groups.
And proceeds to link to this GitHub project of Scott Sauers. Remember: Scott had initially tried to find a non-hyperlinear group, and that project is still on GitHub. The focus has shifted, first to a non-MF group, and then to other related problems that Scott is interested in. How ironic that the motivation to publish this quickly and with no human verification should be the same project that failed to find a non-hyperlinear group, and from there proceeded to find the first non-MF group.
Liu’s paper solves the centraliser problem for hyperlinear approximations of property (T) groups, citing it as an open problem from the Alekseev-Thom paper, and works from there. The first version did not cite the work of Andreas Thom, who had already concluded from that same point. His preprint was publicly available on his homepage, and it is not clear whether the models accessed it. One can only wonder if the situation would have been clearer had Andreas’s paper appeared on the arXiv less than a month after he submitted it. The current version of the writeup acknowledges this. Andreas again:
We [Alekseev, Liu and Thom] all agreed that finding a proof / understanding and condensing the argument / integrating it into the math landscape are separate tasks and should all get suitable credit. If things work out, we will write a joint paper covering all aspects.
Generating a proof, checking its correctness, understanding its mechanism, and connecting it with existing mathematics are becoming increasingly distinct activities.
And now Liu:
I believe that each of these activities deserves credit. This is exactly what is happening with the non-hyperlinear group now, if things go smoothly: I have a proof of an important result; the experts come in to digest and verify it; and in the end we produce a good preprint, post it, and submit it somewhere
What I do not want to see is the following. An AI company () posts a badly written draft, verified or not, on arXiv or on its own website, without any interaction with the community () If you are an expert in the field, should you write a much better version of the proof? If not, the community is left forever with a terribly written paper and no proper explanation. If so, you cannot claim priority for the result () It becomes pure service to the community.
For the non-hyperlinear group, what I hope we end up with is a third path. I only announced the existence of a proof () Then the real experts, Alekseev and Thom, contacted me, and we write a paper together () This requires effort from everyone: nobody should be greedy.
Another thing that was not covered in the first version of the writeup, and that Mikael de la Salle pointed out, is the connection with the Connes embedding problem. This asks whether all von Neumann algebras are Connes embeddable, and the problem of the existence of a non-hyperlinear group is the Connes embedding problem specialised to group von Neumann algebras. But the more general version of the Connes embedding problem had been disproved in 2020 via the milestone MIP* = RE, that is a result about quantum computing. In retrospect, this 50-page construction of a non-hyperlinear group gives a shorter and simpler disproof of the Connes embedding problem (similarly to how the construction of a non-sofic group gives a shorter and simpler disproof of the Aldous-Lyons conjecture). But I cannot articulate enough how glad I am that things happened in this order. The way these two conjectures have been disproved has enriched mathematics immensely, by bringing together different communities, and transferring ideas from one discipline to another. It also led to further applications, like this one, which does not follow from the existence of a non-hyperlinear group. This is much more valuable than solving a single open problem, no matter how big. In this new normal, I mourn all the maths we will not see, but also all the bridges we will not build, and all the gems outside our comfort zone that we won’t be motivated to learn, without certain open problems guiding the way.
Acknowledgements. I thank Vadim Alekseev, Segev Gonen Cohen, Matt Cordes, Alon Dogon, Jihao Liu, Yash Lodha, Marco Moraschini, Andreas Thom and Itamar Vigdorovich for comments on earlier drafts.
- All dates in this text are from 2026. ↩︎
- This is just common practice for me: when I read a new preprint in some depth, I usually send the authors a quick email with some comments, and people tend to be happy about it. The only exceptional thing here was that the result was exciting enough that I had read through the whole paper as soon as I could. ↩︎
- It appears there as submitted on 14 September, which is the date of the most recent modification; I don’t know if this contributed to the delay. ↩︎
- What I am quoting here is the first version of the announcement, which has since changed. ↩︎
Received 21 September 2026, revised 25 September 2026.

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