ICML'26 had two groups of reviewers, one for which LLM use was forbidden and another for which it was not. Reviewers could state their preference and only those who claimed to be ok with forbidding LLM use were assigned to that group. But then, ~500 of the reviewers in the LLM-forbidden group were caught using LLMs through hidden watermarks in the papers they reviewed. As a consequence, ~400 of those reviewers had their submissions desk-rejected (~500 rejections). https://blog.icml.cc/2026/03/18/on-violations-of-llm-review-policies/ via https://retractionwatch.com/2026/03/28/weekend-reads-illicit-ai-use-peer-reviews-commentary-talc-retracted-coauthorship-traded-commodity/

Today's useless advice about making technical online content accessible, from my university's head bureaucrat for online content accessibility bureaucracy (but I repeat myself):

"I would recommend avoiding PDFs altogether. They are extremely difficult to make accessible. If PDF format is absolutely necessary, create a document in Microsoft Office and then save it as a PDF."

Meanwhile, TeX Live 2026 + ltx-talk has been working for me in making pdf-format slide decks that pass all Acrobat accessibility checks, and I have moved on from experiments in using it (https://11011110.github.io/blog/2026/03/01/making-accessible-latex.html) to using it in production for all my course lecture slides. There is no real alternative to some form of TeX for content involving mathematics. This works. And if you're already using LaTeX + beamer, it's not difficult.

New blog post: Making accessible LaTeX talk slides with ltx-talk, https://11011110.github.io/blog/2026/03/01/making-accessible-latex.html

I recently posted about archive.today (also archive.is, archive.ph, archive.fo, archive.li, archive.md, and archive.vn) using its archive links to launch a ddos attack against a blogger they accused of doxing them: https://mathstodon.xyz/@11011110/116028203974257264

That attack triggered #Wikipedia (at least, the English part) to discuss banning archive.today links, and the ensuing discussion turned up evidence that (as part of the same dispute with the same blogger) archive.today had also tampered with its archived content to falsify certain names in old archived links: https://en.wikipedia.org/wiki/Wikipedia:Requests_for_comment/Archive.is_RFC_5#Evidence_of_altering_snapshots

This led to a quick close of the discussion and a consensus to remove all archive.today links from Wikipedia: https://en.wikipedia.org/wiki/Wikipedia:Archive.today_guidance
For the same reasons I have removed all archive.today links from my blog, where I had been occasionally using them as a convenient way to access paywalled content. I suggest that others remove their links as well, lest you unwittingly become part of additional ddos attacks and falsification.

The circle packing theorem (https://en.wikipedia.org/wiki/Circle_packing_theorem): every planar graph can be represented by the tangencies of a system of non-overlapping circles.

This theorem was proved by Koebe in 1936, and popularized in the 1980s by Fields medalist William Thurston as a discrete analogue to conformal mapping and uniformization. Its Wikipedia article was created by Oded Schramm in 2008, not long before his untimely mountaineering death. In his own research, Schramm found deep analogies between random walks on circle packings and Brownian motion. My interests in circle packing relate to its use in drawing graphs, constructing polyhedra for given graphs, modeling soap bubble foams, and finding planar separators. And others have found even more varied applications from the study of discrete symmetry groups of hyperbolic space to methods for visualizing the functional areas of the human brain, spread out into a flattened map.

Now a Good Article on Wikipedia.

The Lambek–Moser theorem is a bijective equivalence between two different-looking mathematical objects: partitions of the positive integers into two disjoint subsets, and pairs of almost-inverse monotone functions from positive integers to non-negative integers.

Real monotone functions are inverse when their graphs are mirror reflections across the diagonal line \(y=x\). We can define something like a graph for an integer function, a staircase curve whose lowest point above any integer on the \(x\)-axis gives the function value; then two integer functions are almost-inverse when these curves are mirror reflections. The attached image shows these two reflected staircase curves for the prime-counting function and its almost-inverse. This pair of functions corresponds to the partition of positive integers into prime and non-prime (composite or one).

By using this equivalence to go from functions to partitions and back, you can sometimes get amazing formulas for sequences of integers that you might not expect to have a formula at all. For instance, the \(n\)th number that is not a \(k\)th power (for integer \(k>1\)) has the formula:

\[n+\left\lfloor\sqrt[k]{n + \lfloor\sqrt[k]{n}\rfloor}\right\rfloor.\]

Now a Good Article on Wikipedia, https://en.wikipedia.org/wiki/Lambek%E2%80%93Moser_theorem

Archive.today / archive.is / archive.ph etc initiates a DDOS attack against a blogger they accused of doxing them (https://gyrovague.com/2026/02/01/archive-today-is-directing-a-ddos-attack-against-my-blog/, via https://lobste.rs/s/z0mdor), sparking calls to blacklist them from reference link archiving on Wikipedia: https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)#Deprecating_and_blacklisting_archive.today

The Brouwer fixed point theorem in action, as exhibited by Github labels: If you try to define a continuous function from text colors to contrasting background colors, there will be some text colors whose background is the same as the text rather than contrasting with it. Discontinuity is necessary to avoid this.

"Why some GitHub labels illegible", @MoritzFirsching, https://firsching.ch/github_labels, via https://mathstodon.xyz/@MoritzFirsching/110015890478886651 – see also https://en.wikipedia.org/wiki/Brouwer_fixed-point_theorem

This is from 2023 so I suspect the specific buggy behavior is long fixed but the phenomenon will recur for any attempt like this one to define a formula using only continuous building blocks.

Generative AI and Wikipedia editing: What we learned in 2025, https://wikiedu.org/blog/2026/01/29/generative-ai-and-wikipedia-editing-what-we-learned-in-2025/, from the Wiki Education project, which mainly interfaces Wikipedia with academic course projects involving editing Wikipedia. Their takeaway message: "Wikipedia editors should never copy and paste the output from generative AI chatbots like ChatGPT into Wikipedia articles."

In more detail, they used Pangram to detect AI-written content, then checked it by hand (finding very few false positives!). They found only a low rate of hallucinated sources. However, more concerningly, in more than 2/3 of the flagged articles, they found sourced sentences whose sources did not contain the information in the sentence. More strongly, "For most of the articles Pangram flagged as written by GenAI, nearly every cited sentence in the article failed verification." This also led to a high rate of wasted WikiEdu staff time cleaning up after the student-made AI additions ("far more time attempting to verify facts in AI-generated articles than if we’d simply done the research and writing ourselves").

Via https://en.wikipedia.org/w/index.php?title=Wikipedia_talk:WikiProject_AI_Cleanup&curid=75478538&diff=1335593937&oldid=1335593653

Purdue rescinds departmental graduate acceptance letters to over 100 students, mostly from China, under an unwritten university policy formulated in response to Trump administration pressure. A faculty quote: "when we’ve asked to get it in writing, [administrators] say they haven’t done it because then somebody could sue us." https://www.science.org/content/article/purdue-blocks-admission-many-chinese-grad-students-unwritten-policy, via https://news.ycombinator.com/item?id=46668801 (and as usual don't read comments there).

The joys of data archaeology...

I happened to be looking up one of my old papers, "On triangulating three-dimensional polygons" (with Gill Barequet and Matt Dickerson, SoCG 1996 and CGTA 1998) when I realized that, although both published versions are open-access, the journal version has figures that have somehow been made completely illegible (all the grayscale is blacked out) and the conference version's figures weren't well reproduced either. My ftp links for alternative copies were long dead (nobody uses nor provides ftp any more). I do still have LaTeX source for the final version, but I couldn't find all the figure files (probably buried as attachments in an associated unix-mail archive). And when I tried to compile it, even without having found all of the figures, the idiosyncratic LaTeX formatting from however long ago caused the text to keep switching mid-paragraph between two very different font sizes.

Fortunately I was able to recover a preprint of the full journal version from one of those academic-web paper scrapers. The text is a little spindly because of the old formatting, but the figures are better. I put it back online at https://ics.uci.edu/~eppstein/pubs/BarDicEpp.pdf and linked it from my publications page.

The main result of the paper, by the way, is that it is NP-complete to test whether a 3d polygon has a non-self-intersecting triangulation. Knotted polygons obviously don't, but the polygons from the NP-completeness reduction are unknotted. Unknotted curves always form the boundary of a disk, but triangulating this disk might require many internal vertices, and the triangulations studied in this paper are allowed to use only the given vertices.

Texas A&M University bans philosophy professor from covering Plato, deeming his Symposium as containing forbidden "race ideology and gender ideology": https://dailynous.com/2026/01/06/texas-am-bans-plato/, via https://boingboing.net/2026/01/07/texas-am-deems-plato-unnecessary-for-approved-thought.html

Bridges between descriptive set theory and the theory of distributed computing through coloring geometric graphs: https://www.quantamagazine.org/a-new-bridge-links-the-strange-math-of-infinity-to-computer-science-20251121/

Quadratrix of Hippias, now a Good Article on Wikipedia: https://en.wikipedia.org/wiki/Quadratrix_of_Hippias

This is a curve swept out by the crossing point of two moving lines, one rotating and one translating. The ancient Greeks discovered that if you have a copy of this curve already, you can use it to trisect angles and construct a square with the area of a given circle, two classical geometry problems that are impossible with compass and straightedge alone. As I wrote on an earlier blog post, https://11011110.github.io/blog/2025/03/22/ancient-greek-mathematics.html, you can also see curves like this when you take a photo of a spinning airplane propellor using a camera with a rolling shutter:

New blog post: Regular link-irregular graphs, https://11011110.github.io/blog/2025/12/13/regular-link-irregular.html

In two recent works, Akbar Ali, Gary Chartrand, and Ping Zhang conjecture that there is no regular link-irregular graph. Here “regular” means all vertices have equal degrees and “link-irregular” means all vertices induce non-isomorphic neighborhoods. In support of this conjecture, they show that it is true for degrees three and four. However, the probabilistic method shows this to be false for sufficiently high degrees.

Congratulations to mathstodoner @csk for being named an ACM Distinguished Member! https://www.acm.org/media-center/2025/december/distinguished-members-2025

I have no idea whether this is related but I am also seeing reports that ICLR is discarding any changes in review scores resulting from its rebuttal phase: https://www.reddit.com/r/MachineLearning/comments/1p8x463/d_iclr_reverts_score_to_prerebuttal_and_kicked/, https://x.com/prajdabre/status/1994428928757567570

It's not a good time to be a program chair of a major conference:

21% of the peer reviews at ICLR (a major annual machine learning conference) were discovered to be entirely written by AI, and "more than half contained signs of AI use". This appears to be in violation of ICLR's terms of conduct, which "prohibited AI use that would have breached the confidentiality of manuscripts". The ICLR chairs write that they are planning to penalize reviewers who did this by desk-rejecting the reviewers' submissions but they say nothing about what they are doing for authors whose submissions received these reviews.

Report in Nature, https://www.nature.com/articles/d41586-025-03506-6, https://archive.is/1cmjJ; details of analysis by Pangram, https://www.pangram.com/blog/pangram-predicts-21-of-iclr-reviews-are-ai-generated; response from ICLR program chairs, https://blog.iclr.cc/2025/11/19/iclr-2026-response-to-llm-generated-papers-and-reviews/; via https://lobste.rs/s/ww6cfs/major_ai_conference_flooded_with_peer

Peter Cameron, as a retired professor still active in research, finds himself locked out of unfree-open-access publication because his university won't use their publication-fee funding for emeriti despite continuing to count his publications towards its research productivity metrics: https://cameroncounts.wordpress.com/2025/11/22/old-age-and-open-access/

A reminder that what you think may be standard arithmetic notation may actually mean something entirely different in nearby cultures: https://commons.wikimedia.org/wiki/File:Obelo-intervallo-cabine-tirrenia.jpg