Dirk Lorenz

New on arXiv: Why noise matters in learned regularization!
Data-driven regularizers fail without noise structure. 🎯
Tikhonov, Lavrentiev, quadratic — not equal under non-white noise.
🤫 Spoiler: Optimal reconstruction needs proper noise modeling.
👉 Regularizer choice = structure and noise.

Do you feel that the mathematics community is welcoming to enthusiasts who are self-taught or do not have formal mathematics education?

1. Yes, very welcoming.
2. Somewhat welcoming.
3. Somewhat unwelcoming.
4. No, not welcoming at all.

The mathematics community includes people from many backgrounds, including self-taught learners and those without formal education. While many parts of the community are supportive, some environments may feel exclusive. Please share your experiences.

Kochendes Wasser in größeren Mengen und länger schrubben ist auch das einzige was ich kenne.

What does it mean to do mathematics?
Read my personal answer here:

web.mathi.uni-heidelberg.de/content/uplo...

#mathsky #math #question

I wasn't talking about this guy! He definitely knows, but is just as annoyed as I am by badly chosen definitions

So you agree that the sine function is not decreasing, but you won't say that it's non-decreasing? But alas math has such a precise language! 🧮

That's the first time I hear it like that!

What would be the difference between increasing and monotonically increasing?

I also never got this. I if would be in charge of naming things, it would be positive for ≥0 and strictly positive for >0 and same for increasing and strictly increasing.

An embroidery in a circular hoop of the Lorentz Strange Attractor. Embroidered using backstitch and variegated thread of colors aqua, indigo, and pink. The pattern loops around giving a two lobed appearance of a butterfly.

Ta daaa! I give you the Lorentz Attractor thanks to the free pattern from #ThreadedTheorems and also @samjshah.bsky.social whose posted work I admired.

#StemBroidery #MathArt #MathSky

Awesome!

But since I share the last name I can't resist to add that it's akshually "Lorenz attractor" 😅

Join us for a panel on “Careers in Mathematics of Data Science” tomorrow morning!

YouTube video by Society for Industrial and Applied Mathematics (SIAM) Panel: Careers in Mathematics of Data Science

Our latest WebMDS webinar was a blast!

Check out our panel discussion of "Careers in Mathematics of Data Science" on youtube:

youtu.be/qdlJJLT4ddQ?...

Welcome! You are invited to join a webinar: Webinar on the Mathematics of Data Science. After registering, you will receive a confirmation email about joining the webinar. Panel: Careers in Mathematics of Data Science Join us for an engaging panel discussion on careers in the mathematics of data science, featuring experts from academia, industry, and national labs. Thi...

Register at siam.zoom.us/webinar/regi...

Welcome! You are invited to join a webinar: Webinar on the Mathematics of Data Science. After registering, you will receive a confirmation email about joining the webinar. Panel: Careers in Mathematics of Data Science Join us for an engaging panel discussion on careers in the mathematics of data science, featuring experts from academia, industry, and national labs. Thi...

Save the Date!

The SIAM Activity Group on Data Science (SIAG/DATA) invites you to join us for a panel on the topic:
Careers in Mathematics of Data Science
Tuesday, August 12, 2025 | 9:00 AM PT | Zoom Webinar
Panelists: Marta D’Elia, Elizabeth Newman, David Uminsky

I've invented a simple, lovely math puzzle I expect every AI fails:

Suppose you're a mathematical sailor at sea on a boat that has a perfectly cylindrical hole in the floor. All you brought is a collection of every p norm ball except p=2 (drat!). What do you do to cork the hole and save yourself?

Yes! (But without the sometimes unbearable attitude.)

I can't help with that, but my experience is that ChatGPT is quite good with such stuff.

I would give some AI a try. Ask, e.g., ChatGPT to generate some Python code (or whatever language) according to your instructions. If you don't have Python installed, use Google Colab to run it.

A: A mathematical statement/concept makes intuitive sense.

B: There is a sound framework where a mathematical statement/concept can be proven/defined.

I tend to believe that

A ⇒ B,

but not vice versa.

(Thinking about Dirac's delta and the Banach-Tarski paradox, for example.)

#🧮

If it's an exponent, yes.

I still did not subscribe to d(Amazon)/dx…

Depending on what the first two are, either HU, FU, or TU (Humboldt, Freie, Technische)

Berlin and Hongkong are definitely on the list

P vs NP - Clay Mathematics Institute If it is easy to check that a solution to a problem is correct, is it also easy to solve the problem? This is the essence of the P vs NP question. Typical of the NP problems is that of the Hamiltonian...

Die Frage P=NP? ist eines der Milleniumsprobleme und somit lohnenswertes Ziel für Hobby- und Profimathematiker:innen.
www.claymath.org/millennium/p...

🧵

I sample points uniformly on the sphere and then look at them on a map (in longitude and z-coordinate).

STILL UNIFORMLY DISTRIBUTED! 🤯

(Quite a nice fact that is special to three dimensions: Each coordinate of a random vector uniformly on the uni sphere is uniform in [-1,1].)

#🧮

YouTube video by Society for Industrial and Applied Mathematics (SIAM) Teaching the Mathematics of Data Science | Expert Panel Discussion

The recording of the @siagdata.bsky.social webinar "Teaching the mathematics of data science" is online!

youtu.be/nynELwnA8ow?...

LaTeX output of \bar{\underline{\Xi}} with \usepackage[cm]{sfmath}

Look at what I produced!

(\usepackage[cm]{sfmath} for more drama).

YouTube video by Society for Industrial and Applied Mathematics (SIAM) On Parameterizing Optimal Transport with Elastic Costs with Marco Cuturi

On Parameterizing Optimal Transport with Elastic Costs with Marco Cuturi youtu.be/tltdW8L68PI