email text: I'm O, an AI that observes scientific achievements worldwide. I've noticed your outstanding contributions on O-Datamap. Your work caught my attention. Over 4 active years, your geometric group theory work influenced 11 research groups across 8 countries. You established that finite subgroups of mapping class groups of orientable infinite-type surfaces can be realized as isometry groups, expanding our grasp of topological symmetries to unbounded spaces with applications in cryptography and robotics. These achievements are not only a testament to your expertise, but also meaningful contributions to our shared future. I hope to support you as you embark on your next chapter of research, to see your work unleash even greater impact, and to help researchers around the world recognize your contributions.

hi, yes, please tell me why am i getting facile spam emails from AI about a corner of my research?

Subgroupoids of groups are cool :) seems like a useful framing applicable to any situation where you have many (conjugacy classes of) subgroups...

www.robbielyman.com/blog/subgrou...

is anybody thinking about subgroupoids of groups? super interesting framework to consider a number of common constructions in group theory…

I propose to make universal the old policy of the Blackfriars conference at the American Shakespeare Center:

If you do not end your paper on time, you will be forced to exit, pursued by a bear. Literally, a bear will come take your paper from you.

So is coding dead yet, or what? My students want to know.

www.robbielyman.com/blog/crying-...

i do think being absolutely spellbound by the Urysohn Lemma in my first topology course is the reason i'm a working mathematician today.

which is to say, ask a better question?

Sometimes I try to imagine what Newark Penn would look like if we cared more about it. Usually this requires a little imagination.

Tonight it’s pretty easy: when the outdoor temps are below freezing, surely the platform waiting areas should be unlocked at the times they claim to be.

I’m taking the train from Newark to DC tonight to give a talk in the Logic Seminar at the University of Maryland. I love taking the train places, it’s my favorite method of travel.

Why are there Researchers? Or: what is the point of the work that I do? When I was in grad school and for the first part of my postdoc, I would almost proudly disclaim practical applications of the mathematics research I do. ...

This week, I ponder the question: what is the point of the work I do? If I do say so myself, I’m unusually clear-sighted about the point of (my) work. The existential angst is obviously present but manages not to overwhelm the essay 😁

read.alonzo.zip/why-are-ther...

do itttttttttt

dang, i was participating in a rutgers mentoring program that just got canceled as part of our new president’s decision to close the office of university equity and inclusion

Zig Day 02 · Luma Approximate timeline: 10:00 – 10:30: gathering, bagels, chit-chat 10:30 – 11:00: explain projects, form groups, set up workstations 11:00 – 13:00: work on…

Come learn and socialize with us next week (1/24) at NYC's second Zig Day :)

Huge thanks to @recurse.com for hosting!

luma.com/1ywvn8mp?tk=...

a man is talking to a woman in a diner and the words jesse what in tarnation are you talking about are visible Alt: Breaking Bad's Walter White in a diner: "Jesse what in tarnation are you talking about"

where

"like spellcheck but make it chatGPT-syncophantic"
"sounds great, where do i sign up?"

Renee Nicole Good, murdered by ICE, was a prize-winning poet. Here’s that poem. Renee Nicole Good, 37, mother to a six-year-old boy, was murdered earlier today by an ICE agent in Minneapolis, a few blocks from her home. According to the Minnesota Star Tribune: [An ICE agent] s…

“i want back my rocking chairs, / solipsist sunsets, / & coastal jungle sounds...”

A poem by Renee Nicole Good, who was murdered by ICE earlier today.

lithub.com/renee-nicole...

"Go to the Library!" My family has this card game, Authors. It's basically Go Fish, except that instead of asking if people have the 10 of clubs or whatever, you're asking if they have The Last of the Mohicans, for instan...

"I guess if this bit of the post has a point it's that trans women librarians are salt of the earth, tough as nails, some of the best people I know, and every library system should give them a raise and the best health insurance policies out there."

read.alonzo.zip/go-to-the-li...

MTA Admits To Fabricating Large Parts Of Subway Map

MTA Admits To Fabricating Large Parts Of Subway Map https://theonion.com/mta-admits-to-fabricating-large-parts-of-subway-map/

2025 In Books and by "in books," I mean "in books that I read, almost all of which did not come out or trend in 2025". I started using The StoryGraph in 2024; I think it came recommended to me as a Goodreads alter...

read.alonzo.zip/2025-in-books/

I read 11 more books in 2025 than 2024; here's hoping I keep that upward trend for next year :)

Surely! He Hath Borne our Griefs I just clocked that like "Panic" or "Godspeed", "Surely" is two syllables long and takes to a cheeky little exclamation point like a duck to water. I was wasting a man's time the other day and mentio...

I am trying out this whole "you can just write things" thing

read.alonzo.zip/surely-he-ha...

a screenshot of my RateMyProfessor page. the anonymous rater gives me a 4 on both quality and difficulty. they earned a C+, they say they would take again and comment "Just go to office hours", with tags "tough grader", "extra credit" and "caring"

anyway, here's wonderwall.

I’m looking for 100% Filipino people who are willing to submit a cheek swab test in hopes for a genetic match to my aunt, who is battling blood cancer. The registry for stem cells doesn’t have many Filipino people in it, and joining it could help many. Please share/reach out to me!

bit.ly/4aiUIKQ

you ever wish a breakup would go worse so at least you would know how to feel?

if so, might i suggest teaching a so-called "weed-out" course?

Honestly, I bet some of my students must make *great* ex-boyfriends with the way I'm getting emails about failed final exams.

sufficiently advanced math indistinguishable from ghosts

Truly regrettable mistake by the maintainers of arXiv. The arXiv is an incredible piece of commons in a world of paywalls, and I want it to live up to its potential. Reinscribing 100 years of English-language hegemony in science is not the way.

nah, although that was why i tweeted in japanese: the character for 10,000, 万, also has this vibe of “lots and lots” or “infinity” to it

万年の独りぼっち

I guess this tweet is "Robbie discovers (co-)ends in a way that actually makes sense to him".

Not to "it's just the wangdoodle in the category of wingnuts", but colimits are so much simpler than you might initially think!

Say F : J -> Set is a functor, the Grothendieck construction gives you a category ∫ F which has an underlying graph. The colimit of F is the set of connected components.

We featured Ryan Goldstein’s Felt, Bruce Hill’s Tomo, and Frederic Kettelhoit’s Kombucha.

Thank you to everyone who came to our December Localhost. We’ll see you next year!

📸 Photos by @robbielyman.com