iiinova — where your digital self keeps evolving

Tien Chih @tienchihmath.bsky.social · 46m

von Neumann ordinals, but with committees.

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Tien Chih @tienchihmath.bsky.social · 06/10/2026

Two untamed beasts wander a campus.

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Ian Carrillo @iansociologo.bsky.social · 05/10/2026

The conservative quest for diversity of thought was always leading toward mandatory reading of approved authors.

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Tien Chih @tienchihmath.bsky.social · 05/10/2026

69th derivative would take a little more work.

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ꭓle Ormsby 𓆙 @e-infinity.space · 05/10/2026

It's a graph. It's a matrix. It's a determinant. The monomials in the expansion of the determinant encode the spanning trees of the graph. It's the Matrix-Tree Theorem. e-infinity.space/matrix-tree/ 🧮

Screenshot of the app in action. The triangular prism graph C_3 x K_2 is displayed, and it's "edge label enriched" Laplacian is to its side. The determinant of the reduced Laplacian gives a big ol' polynomial whose monomial terms encode the edges participating in spanning trees. They're color coded, and the corresponding spanning trees (in corresponding colors) are displayed below.

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Jeremy Diamond ☕️ @dmnd.me · 04/10/2026

Lmao arxiv.org/pdf/2404.00732

An Abundance of Katherines*
The Game Theory of Baby Naming
Katy Blumer-Kate Donahue',
Katie Fritz', Kate Ivanovich', Katherine Lee', Katie Luo', Cathy Meng', and Katie Van Koevering
'Cornell University†

Abstract
In this paper, we study the highly competitive arena of baby naming. Through making several Extremely Reasonable Assumptions (namely, that parents are myopic, perfectly knowledgeable agents who pick a name based solely on its "uniqueness"), we create a model which is not only tractable and clean, but also perfectly captures the real world. We then extend our investigation with numerical experiments, as well as analysis of large language model tools. We conclude by discussing avenues for future research.

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ꭓle Ormsby 𓆙 @e-infinity.space · 02/10/2026

I'm speaking in TATERS today at 2pm Pacific / 5pm Eastern on the Pontryagin-Thom construction in algebraic geometry! Come for the pretty slides (see e-infinity.space/files/taters...), stay for the framed correspondences and principal quadratic divisors.

Screenshot of TATERS opening slide:

Kyle Ormsby · Reed College · October 2026
The Pontryagin–Thom construction in algebraic geometry
Count the points in a fiber. Attach a sign to each. In algebraic geometry the sign becomes a unit, the count becomes a quadratic form, and the relations come from the zeros and poles of rational functions.

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Tien Chih @tienchihmath.bsky.social · 02/10/2026

So there was always a matrix calculator, but now I want to see what one can do to illustrate linear transformations, independence etc.. FYI the matrix also works for desmos3d!

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Tien Chih @tienchihmath.bsky.social · 02/10/2026

It speaks to their level of understanding and engagement...but it also speaks to how well designed and scaffolded these inquiry activities are 😎.

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Tien Chih @tienchihmath.bsky.social · 02/10/2026

My students in Linear Optimization this year are so good at looking at a little toy example and the activity associated with it, and anticipating/predicting all the major ideas and results associated with it.

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Tien Chih @tienchihmath.bsky.social · 01/10/2026

I was about to comment but you got there first!

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サッカー bones @doctorbones.bsky.social · 30/09/2026

We are hiring for two TT positions, one in Combinatorial Algebraic Geometry and one in Math Ed. Come work here! www.mathjobs.org/jobs/Virgini...

mathjobs.org

MathJobs from the the American Mathematical Society

Mathjobs is an automated job application system sponsored by the AMS.

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Tim Hsu @timhsu.net · 25/09/2026

Pleased to announce that San Jose State Math/Stats (www.sjsu.edu/math/) is hiring two tenure-track faculty this year, one in discrete math/graph theory and one in statistics/data science! More details and application form in thread below:

sjsu.edu

Department of Mathematics and Statistics

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Tien Chih @tienchihmath.bsky.social · 28/09/2026

The "unlike" is wholly inappropriate.

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Tien Chih @tienchihmath.bsky.social · 28/09/2026

"Unlike large math or physics courses, humanities courses are often best delivered as discussion seminars", the "unlike" here is an odd addition. www-chronicle-com.proxy.library.emory.edu/article/the-...

www-chronicle-com.proxy.library.emory.edu

Emory Libraries Resources Terms of Use - Emory University Libraries

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Barbara Fantechi @barbarafantechi.bsky.social · 27/09/2026

Maths IS best taught* in a class where students are encouraged to interrupt and ask any questions whenever, which places a natural cap in class size. *If the goal is students learning. The ability to pass a multiple choice test is a completely different goal.

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Tien Chih @tienchihmath.bsky.social · 28/09/2026

That last sentence is a doozy. "[He] holds all the cards", name one card.

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Tien Chih @tienchihmath.bsky.social · 27/09/2026

I interviewed for a job once and I had a really nice blazer laid out on my bed, and it was still there when I unpacked my stuff in the hotel, so I spent the whole day with a grey ragged zip-up hoody from grad school as my outerwear. And well, I'm going up for tenure now at said place 🤷.

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Tien Chih @tienchihmath.bsky.social · 26/09/2026

This is why I hate *hate* the criticism that if there's a set of fans who think the show is saying X, when it's obviously saying Y, then it's the creator's fault for not making that clear. We should not make things exclusively for the dumbest people on the planet.

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emilyriehl.bsky.social @emilyriehl.bsky.social · 25/09/2026

I was part of a group that met last week to try to propose recommended changes to the structure of math PhD programs in an age of AI. Our report, together with a collection of related resources, is now available here: cmsa.fas.harvard.edu/aimathphd_su...

cmsa.fas.harvard.edu

Summit on PhD Math Education in the Age of AI - CMSA

On September 17–18, 2026 a group of 24 mathematicians met at Harvard to grapple with the changing landscape for mathematics PhD programs in the age of AI. We produced recommendations given […]

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Steven Clontz @clontz.org · 26/09/2026

If you haven't played with pretext.plus in a while, we just spruced up the editor. It's looking pretty good even on mobile!

Screenshot of my intro to Topology book on pretext plus taken on an Android device. Design elements akin to Google Docs in the menu bar and VS Code for a sidebar hopefully provide an improved user experience.

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Chad Topaz Queer DEI Race Traitor @chadtopaz.bsky.social · 25/09/2026

I hereby volunteer to guest lecture about racial justice (and data) for any UT classes that will have me.

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Tien Chih @tienchihmath.bsky.social · 25/09/2026

...otherwise, you have students who "know" \int_0^1 \frac{dx}{x^2} diverges, but don't know what happens to \int_2^3 \frac{dx}{(x-2)^2} without grinding through the integral and limit, because they don't think to just make the connect back to what they already know.

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Tien Chih @tienchihmath.bsky.social · 25/09/2026

... reference, they *couldn't* know what goes where. The fact that it's the whole circle and not just the first quadrant really drives this home. I think it's a good skill to develop in students to be like "X happens here, how can we use that over there?" and exploit similarity and symmetry...

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Tien Chih @tienchihmath.bsky.social · 25/09/2026

I'm a big picture/diagram guy myself, but I don't think thats what these tables emphasize. I think they reinforce a notion that math is something to be memorized or referenced and not reasoned with, and that these values were somehow chosen arbitrarily or capriciously, and that without this...

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Tien Chih @tienchihmath.bsky.social · 25/09/2026

Thats what I tell them if they need to remember anything, the precise values maybe hard to obtain from first principles. But then the bigger ones go where they go.

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Tien Chih @tienchihmath.bsky.social · 25/09/2026

I don't understand why you would want to "memorize" anything but the first quadrant. I also don't understand what there even is to memorize besides "big x go right, big y go up".

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Tien Chih @tienchihmath.bsky.social · 23/09/2026

For succ(succ(2+0))=succ(succ(2)), does one have to say "by algebra"?

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

lol, traumatizing isn’t the right word. Honestly I was amazed that anyone could possibly give a fuck about my morning annoyances.

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

Just don’t post about coffee whatever you do.

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

To add insult to injury, any sample of a distribution like this is finite, so it has a sample mean and deviation, but such distributions resists the CLT, so any sort of intro stats stuff we would want to do would be invalid!

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

Since it’s just calc 2, I just say we assume the probability distribution density is p(x) = 2/pi*1/(1+x^2). We can show that \int_0^\infty p(x)dx = 1, so it’s a legit PD. But the mean is \int_0^\infty xp(x)dx which is undefined.

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

So let’s say you have an archer with a magic bow that shoots an arrow indefinitely far at a straight length. They are standing one kilometer away from an infinitely tall wall. They pick an angle in (0,pi/2) and shoot, X denotes the height in km.

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🇵🇸Tim Henke (tɪm 'ɦɛŋ.kə) @timhenke.bsky.social · 22/09/2026

Btw if you're a junior at a conference: make a group chat with the other young people! Go to dinner and undertake activities together! You get to socialise, network, and collect contact information. I do it every time, it's very much worth it

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

You could do 16 face cards for the different suits.

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

Went a bit off the rails in Calc 2 today talking about probability distributions without means.

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

This is journalistic malpractice.

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Tien Chih @tienchihmath.bsky.social · 22/09/2026

I got to play set with students and colleagues today during lunch, so today was a good day.

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Tien Chih @tienchihmath.bsky.social · 21/09/2026

It always amazes me to see what weird shit people get fixated on.

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Tien Chih @tienchihmath.bsky.social · 21/09/2026

Another small life annoyance, posting about a mundane nuisance in the early morning and then having a bunch of WELL AKSHUALLY’s reply.

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Tien Chih @tienchihmath.bsky.social · 21/09/2026

One of life’s little injustices is that you have to make coffee before you’ve had coffee.

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Marco @malmeida.bsky.social · 21/09/2026

shout out to professors that help unveil some of the Hidden Curriculum to students

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Dr. Courtney Gibbons (she/her/xlookup) @courtneygibbons.phd · 20/09/2026

#PreTeXtGang, I would love to know your thoughts about building Lean 4 exercises directly into a book (pros? cons? possible? impossible?), either directly or as Parsons problems or similar...

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singular locus sarah @scgriffith.bsky.social · 20/09/2026

this but unironically

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