iiinova — where your digital self keeps evolving

Ben Spitz

@diracdeltafunk.bsky.social

128 followers 38 following 170 posts

Sheaf Herder. I believe in you 🔥 benspitz.com

Posts Replies Media

Ben Spitz @diracdeltafunk.bsky.social · 10/12/2025

Same as the e^{ix} thing but said differently: We start with a 💥GEOMETRY FACT💥 A tangent line to a circle at a point p is orthogonal to the radius of the circle at p.

A yellow circle with center O, and tangent line T to the circle. The line segment (radius) from O to the point of intersection between T and the circle is shown. The radius is orthogonal to T.

140

Ben Spitz @diracdeltafunk.bsky.social · 17/09/2025

Very very happy with this project we ran at the M2 workshop this summer in Madison -- it is now possible to do compute Ext, Tor, etc. of C_p-Mackey functors by computer! The image below shows how you can use the package to compute a free resolution of a C_p-Mackey functor.

130

Ben Spitz @diracdeltafunk.bsky.social · 09/09/2025

... can this be simplified at all? n and m are fixed positive integers, p is a fixed real number between 0 and 1.

$\sum_{i=0}^n \sum_{j=0}^m \binom{n}{i} \binom{m}{j} p^{i j} (1-p^i)^{m-j} (1-p^j)^{n-i}$

662

Ben Spitz @diracdeltafunk.bsky.social · 19/08/2025

My claim to fame is being the first person (I think) to find 4×4 examples of this

1101

Ben Spitz @diracdeltafunk.bsky.social · 18/08/2025

Uh ok now with a non-transparent background

130

Ben Spitz @diracdeltafunk.bsky.social · 18/08/2025

You've inspired me to make this banner for my course this semester

110

Ben Spitz @diracdeltafunk.bsky.social · 17/08/2025

You cast a wide net! Today I'm cleaning the house and knocking out a cabinet so I can install a dishwasher 🙏

150

Ben Spitz @diracdeltafunk.bsky.social · 17/08/2025

It's not given much explanation in the paper... here's my understanding. The paper shows that the total number of rings grows faster than the number of local rings with m²=0, but grows at the ~same rate as the number of local rings with m³=0. So, maybe the local rings with m³=0 are ~everything!

340

Ben Spitz @diracdeltafunk.bsky.social · 14/06/2025

BABY FROG

030

Ben Spitz @diracdeltafunk.bsky.social · 13/06/2025

Sneak research preview -- fun pictures coming soon In this paper, we also get to take a limit as p (a prime) approaches 1 :^)

181